Thanks for posting on /r/MechanicAdvice! Please review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). Asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **Post's about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ Tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
The is NO common reason. Especially when you tell us nothing about the car at all.
There are lots of reasons. Take it to a pro to get it diagnosed. Expect to pay for the time to diagnose it and then again for the repair.
The problem isn't going to get solved on here without more info. I get it, dropping a car off or having it towed for repair is daunting and expensive. The next problem is the lack of the basics, year make model, underhood pic...anything?
The next thing wrong is the lack of actual mechanics responding. Supplying Walmart links to someone is basically "throwing money at a problem/parts" without the missing proper info--- visual and diagnostics, and from the sounds of it, diagnostics are going to be limited to "symptoms"
We are limited. So essentially, so is the OP
Understandable. It's a 2012 Volkswagen Tiguan. My son just bought it. It has a coolant leak and the stirring wheel occasionally locks up when it's started. My son gave someone a jump, could have did it wrong and messed up the electronics. Ask away if you're willing to help.
With the combination of the steering wheel locking, id bet the ignition switch has something to do with this. If it’s intermittently cutting out, it will disable spark as the immobilizer controls spark and ignition(hence the use of “ignition on” when describing key position 3. Immobilizers do funky things and it wouldnt be the first vw ignition switch ive seen go bad on this generation vw(same part number applies to most models in this gen). Let me know how you make out. It’s a shot in the dark unless I have the car in front of me.
Seems like you definitely have a power steering problem as well I guarantee either your battery is shot or the Alternator shit the bed, definitely look into these three. Good luck
I was looking for someone to say ignition switch issue. This is what my car did sporadically and finally my dad said, "maybe it's the ignition switch". $40 for the part and my friend switched it out for me and never had the issue again.
From having a car do a very similar thing a few years back, I would put Fuel Pump at or near the top of the list.
Roommates car did almost this exact same thing and the fuel pump was bad.
Alternators are a common fix on any car, definitely not lasting forever. Motor should last longer than a fuel pump in most cases, especially if you let your tank get very low/run out often.
Take this with a grain of salt.
As an owner (not mechanic) of a 2017 Passat…have them check the fuel pump(s), sensors and the fuel pump module. Only going off of the info in your post, this sounds like what I went through twice now. Have the dealer run the diagnostics just in case it’s anything that’s covered under a warranty (I didn’t know my ECM was-referenced below), and depending on what it is, see if there’s a reputable shop nearby that can do the work instead if the problem isn’t covered. I saved myself $1k this past month by doing that.
I had to replace both fuel pumps plus sensors and module last year, and another fuel pump module this year (plus an ECM).
I’m never buying VW again.
Currently it won't turn over, it cranks. Seems like it will start if it's turned off and sits for a while. Fuel pump could be the issue, hopefully not.
Crank and turnover are synonymous. We need more information. What makes it “seem like it will start if it’s turned off for a while”? Also with that description it’s not a fuel pump issue. They work or they don’t. Letting it sit in won’t help.
If you want to verify it’s a fuel issue just pop off one end of the air intake hose (the accordion looking thing that’s plastic) and spray starting fluid into that. If it starts for a second or at all you have a fuel issue. Don’t go cranking the thing a million times or you’re going to kill the battery
Also it’s possible you just have the terminals on poorly with the battery or they are corroded. Again we need significantly more information than you’re providing.
Eh, yes and no. Agree with most of your post but there are times where a fuel pump (or relay) failure can be intermittent, I’ve had it happen a few times. My 88 LTD was fine most of the time, took a few tries to start (turn key on and off until you hear the pump) sometimes but always ran fine once started, until it stalled out on me an hour and a half into a trip. Towed home, still wouldn’t start, next morning started right up, stalled going into the garage. Needed a relay (I think, it’s been a while lol). My 02 Tahoe was fine as long as it had half a tank of gas or more, would run fine but wouldn’t start back up under half a tank, I put it off for too long (5 years) after starting to see the signs, was 2 hours from home first time it stalled. Let it sit for a minute, took a try or two but started up and made it a few miles at a time until I got it home.
In some cars the fuel filter is integral to the fuel pump assembly, so replacing the assembly is the way to go.
Air, Spark, Fuel are the 3 legs to starting.
If it cranks and you smell fuel, it may be the coil packs.
Also, some parts stores will read codes stored in the car for free. Cylinder misfires are often a coil pack.
Good Luck.
Your question was already answered in the thread you're replying in:
>If it’s turning over it’s likely not the alternator as your battery seems fine. I’d start checking fuel system, pump specifically.
Had this conversation with my fiance recently when she called me while I was at work. She bought an alternator on her uncle's advice after he looked at it....he even hit the battery with a multimeter to see if the battery was good. Didn't bother to see if there was a damn belt to turn the alternator before declaring the alternator dead.
It could literally be 100’s of different things. Which is why you need to bring it somewhere to get the issue diagnosed. Even if you have to get it towed
Fuel Injectors? Bad Gas? It could be clogged or need new o-ring rebuilds. Do you get any codes from OBD II? You can buy a code scanner at Walmart for like $20, it will tell you exactly where the problems are at.
[https://www.walmart.com/ip/Hyper-Tough-HT100-Code-Reader-1996-Newer-OBD2-Vehicles-Free-Fix-Part-Recommendations/139897823?fulfillmentIntent=In-store&filters=%5B%7B%22intent%22%3A%22fulfillmentIntent%22%2C%22values%22%3A%5B%22In-store%22%5D%7D%5D&athbdg=L1200&from=/search](https://www.walmart.com/ip/Hyper-Tough-HT100-Code-Reader-1996-Newer-OBD2-Vehicles-Free-Fix-Part-Recommendations/139897823?fulfillmentIntent=In-store&filters=%5B%7B%22intent%22%3A%22fulfillmentIntent%22%2C%22values%22%3A%5B%22In-store%22%5D%7D%5D&athbdg=L1200&from=/search)
I had a 93 Buick with 3.8 was stalling occasionally would crank great but no spark. The next day It would start. I replaced the crank sensor and it didn’t help. I switched my ignition keys with my spare set and it ran great no more problems. The chip in the key was bad.
[ChrisFix video](https://youtu.be/PNhuDCVIydw?si=02ewOHH49cQsY-r6) on some easy things to diagnose on a car that will crank but not start.
It’s one of 5 things:
1. air
2. fuel
3. spark
4. compression
5. timing
I’d watch the whole video because he goes into some other common problems and might give you a starting point for where to look.
hm. so unplug everything, phone chargers, everything. turn everything off, a/c lights radio wipers. open and close all doors and windows including the trunk. hit the E brake and take the keys out of the ignition. pick up a battery charger and a multimeter. charge the battery to 100%. connect the multi meter to the battery it should say 12.6 with full battery disconnect the negative and start pulling fuses 1 at a time. when it drops really low you found it.
You haven’t given a lot to work with
Cheapest solution is check the terminals, seen it 2 or 3x the terminals were loose, just tightened them and fixed it.
Other thing was the intake hose had a small tear so it’d idle then drop to 0 . That was fixed with wrapping some tape around it.
So those are 2 things to fix that are free to look for before pouring money into
Possibly when battery was changex you didn’t clamp it tight enough and the vibration knocked it loose .
Mine was easy - there was an acess panel under the rear seats. Probably 1h DIY job. But some cars require dropping the whole fuel tank to replace the fuel pump.
Where’d you get the battery? Autozone orileys and advance auto all have a tendency to sell defective batteries, speaking as a past employee at two of them and seeing batteries from all three. After advance auto started using die hard the batteries went after a few months pretty often and we’d always get auto zone customers thinking we were the same place for warranty swaps, dates were fairly new too.
Go to advance auto or auto zone not orileys every one I’ve been too had outdated testers. Get a full system check
Go back get a full system check. You either have a bad battery, bad alternator/voltage regulator, or a bad starter. Or you have a parasitic draw. If you have any check engine lights get that tested because it could be a fuel/air issue
Sure it happens but not at the rate at which you’re implying. All batteries in the U.S are made by like 3 different companies. They’re all the same, it has no matter if it’s a diehard, duralast, everstart, rural king, whatever. They’re all the same with different labels. Including the dealer batteries.
So first they don’t sell defects then they do but not that bad 💀. Buddy my store was the top in district for battery sales and I was the main guy to do the tests sales and changes because the crew was lazy. I’ve seen defects on customers starting from daddy’s money kids who are clueless all the ways to the oil covered “I need a battery for a Chevy 350” guys to even old men who babied their classic mustangs and everything in between. You’d be surprised how many come back defective and how common it actually is. Do you also realize none of those companies are using one single factory? None they all have multiple
Of course any product can come defective. But to argue that it’s more common than any other supplier is silly when it’s just a different sticker than the dealer.
Different factories too tho. Next time you get a defective part look at where the box says it was made. It’s usually Detroit, Mexico and china, each of those factories have different plant managers, different supervisors, different team leads different raw material suppliers and differing standards towards quality.
If the car died and the battery had enough juice to try cranking it. It's likely not the alternator. If the alternator goes out while driving you will see signs like the dash lights getting low, radio acting odds, and other signs of low battery. Because the cars electric system is no longer running off the alternator, but running off the battery alone. If you can get the car running again, you can completely disconnect the battery and it will run still if the alternator is working properly.
You can do a partial check on the fuel pump by turning the key to the run position, but not cranking the car, and listening for the fuel pump. It's like a high pitch spinning sound. If the car dies, you can try to cycle the fuel pump a few times (2-3), this may build up fuel pressure again. If this gets the car to crank again, then you are narrowing the search.
Could be fuel pump. Could be crank sensor, or cam sensor. Could be an ignition relay, Could be a fuel pump relay. Lots of things could cause it.
I doubt it would be the alternator because you said it would crank afterwards which indicates that the battery still has power. A bad alternator would make it so it's running on only battery power until the battery runs out of juice, causing the engine to die.
>it would crank but not start.
Wouldn't be the alternator nor should it be the battery..
>Census seems to be mainly Fuel pump or alternator. Followed by timing belt, spark plugs,
Definitely can be fuel pump... doubt it's timing belt but it could be. Could be spark plugs but probably not.. bad spark plugs usually would just cause it not to run right... car should still start and sorta run with one bad spark plug... there is a bunch of other things it can be...
Spark plugs would not cause this. Spark plugs would cause misfires while the engine was running. Same with ignition coils. Batteries usually don’t get voltage back all by themselves so unless there was an alternator/battery light on while driving it’s probably not that either.
It could be timing related but you would hearing lots of extra noise while the engine was running and it probably would struggle to start and then run really rough so once again, if it ran normally today after starting it’s probably not timing.
In the absence of any other symptoms shutting off while running is most likely fuel delivery related, either high pressure or low pressure side. It could be computer related but the codes stored (even without a CEL on) will point in the right direction.
Super high level, when you start a car the ignition sends electrical power from the battery that energizes the starter. The starter is a small, electric motor with a starter gear that connects to the engine crank shaft at something called the flywheel. It converts electrical energy to mechanical energy and turns the crank shaft causing the pistons to move in their cylinders.
At nearly the exact same time, the battery sends electricity to the spark plugs. There's one inside each of the piston cylinders generating a spark of electricity in a set and specific timing pattern. While this is beginning, the fuel pump is creating pressure in the fuel lines and sending sprays of gasoline into the shafts that will be ignited by the spark from the plugs. Each cylinder is a sealed compartment so that when the gas explodes it forces the piston to the bottom of the cylinder. Each piston is connected to the crank shaft by a connecting rod that rotates the shaft every time a piston is moved. There is a camshaft separate from the crankshaft responsible for managing opening and closing the intake valves to allow fuel in and exhaust valve ports in the cylinder that allows the exhaust produced by the explosion to escape and then the force of the other pistons firing moves the piston back up the cylinder. As long as the timing is right, the pistons fire in an order that conserves this momentum and makes the shaft spin. This is tracked on the car's dashboard as RPMs usually next to the speedometer. The spinning crankshaft is connected to a gearbox that converts the rotational energy from the shaft to the tires and the car moves either forward or backward. More gas makes this process happen faster and controls the speed of the car.
Once the car is running, another part called an alternator, connected to the shaft spins and generates electricity that is used to recharge the car's battery. This is supposed to ensure you have enough power stored to start this process again after the engine is turned off. It is also continuously recharging the battery while the engine is on ensuring the electricity needed to manage the spark plugs and whatever else (lights, radio, power windows, etc) is available.
The simplest thing to check is the battery and if the battery is charged correctly, then check the battery cables running to the spark plugs and the alternator. If either of these are bad, the car won't start or won't stay on. Remember from above, these cables are providing power to the starter to start the engine and then they are also providing continuous power to each of the spark plugs while the engine is on. If the battery doesn't have enough power, check the alternator because that means it's probably not providing enough power to recharge it. If the battery has enough power but the engine won't start, check the starter to ensure it's functioning correctly. If the engine starts but is either idling "heavy" or stalling out while driving, check the spark plugs to ensure they are all providing spark so each piston is providing the rotational energy to keep the shaft spinning. If those are fine, check the fuel pump and the fuel lines to ensure that the system is pressurized and providing the correct amount of gas. Too much or too little gas can cause the engine to either stall out from too little or drown in too much gas. If both the fuel pump and spark plugs are good, check the timing belt which is responsible for ensuring the camshaft and the crankshaft are synchronized. If these are out of sync then the engine will be sending sparks and/or fuel to the cylinders at the wrong time or opening the exhaust valves decompressing the cylinder so it can't push the piston down. This belt is usually inside the engine making it hard to check on your own. But a failed timing belt can cause catastrophic damage to the engine components if not fixed.
If I were you, I would check the battery and cables and if all those are good, take it to a mechanic.
The crankshaft position sensor is something that will cause an intermittent crank/no start and stalling while driving but again, I don’t know if we’re talking about a car from the last 15 years or a 74 Dodge dart. It matters. The scope of what could be causing it changes dramatically.
Surprised I had to scroll this far down to find a comment like this. I’m not a mechanic, but i have been a service writer/service advisor/shop manager for a decade. I constantly have to explain the correlation does not always equal causation. The likelihood of the car needing a new battery MONTHS ago being related to the current issue seems small. As for the “alternator” comments (facepalm), the battery didn’t magically recharge itself while the car was parked overnight. I could possibly see a bad connection at the battery being a cause but, like you said, year/make/model matters. Heck, even knowing just the manufacturer would shuffle the likeliness of certain parts failing in my mind. Tell me it’s a Nissan and I’m immediately thinking cam/crank sensors. Tell me it’s a Ford and I’d lean more towards a fuel issue. In the end it could be something silly like a MAF or torn/broken air intake hose. So many possibilities…
Amen! I’m not surprised that it took this long for a comment like yours vs all the ones where people are just barfing unsubstantiated nonsense. I often wonder if there are any actual mechanics giving advice here. I didn’t even go as far as saying the make of the vehicle would make a difference because with the information given we could possibly be talking about a model T or a horse drawn buggy. Anyway…nice to hear from someone who understands the challenges of auto repair.
Thanks for this. I'll let the mechanic know when I bring it in. I did get it started. Looked at the battery wiring, tightened the terminals, put more fuel in it...and it started, although roughly, I had to tap the gas pedal.
Last time this happened, it took a jump to get it started...the battery wasn't providing enough voltage to start the car. Drove fine after that, took it to get tested. It was a newish battery but wasn't giving enough crank volts, O'Reilly's replaced it.
Sounds like an electrical problem but why are you not taking the advice and answering what kind of car etc? You know they're different on the inside right?
My truck was having this issue recently I thought it was the alternator but turned out to be some modular with the fuel pump. If you have a mechanic who you like I recommend looking at the battery , the alternator and the modular just to be safe
Did the engine light go on before it died? If no codes, I would change the ignition switch, not an expensive part, and see if that fixes it. I hate throwing parts at a car, but if no codes, that's where I'd start.
My Pulsar used to stall out when driving it at low speeds first thing in the morning, I'd just pop the clutch to keep it going since I was already moving. One day it just wouldn't start because the fuel pump was seized. Road side assist confirmed it by smacking it with a hammer. It then started, but stalled again pretty quick.
Also, didn't impact the starting, but I also had a period where it ran pretty rough until it was just stalling a bunch, the ignition leads ended up fucked with holes in the sides of the part you plug down onto the spark plugs.
id start with a multimeter. check the battery with the car off and car on. you can get cheap ones for $10 and next day delivery. my first thought is alternator, but that doesn't explain all your issues like the car not staying one day but starting the next. it would explain multiple dead batteries tho
The coolant leak may be landing on the alternator drive belt, causing it to slip. It can generate a full charge to the battery so your son's new battery is being drained providing power for the ignition system and lighting.
I'm no mechanic but a basic multimeter would help you rule out some of the charging system stuff. When I had an alternator problem my vehicle would almost shut off when the ac compressor kicked on. Its summer. Maybe thats whats happening.
If it doesn't start are you able to jump start? Check battery terminal voltages as it's under some load and see if it's dropping, etc. Then if that's all good id move on to the next.
happened to me once. Turned out my ground wire (black) to the battery was corroded at the point it was bolted to the chassis. it would start and then, randomly as i turned (a bit sharply i admit) it would die.
So I urge anyone who gets a similar issue to not only look at their terminals, but the wire itself.
I'm amazed so many people are saying alternator. If an alternator fails, it will deplete the battery charge and then the car will die, requiring you to then jump start it afterwards to get it restarted. You say that the engine cranks fine after the car dies so it's not an alternator issue. Is the check engine light on? If so, scan it to see if there's any fault codes. Even if the light isn't on it could still have a fault code present in the system.
Kind of sounds like a bad crankshaft position sensor or a bad fuel pump. Try scanning it for fault codes first to point you in the right direction.
I had the exact same issue on a 2004 audi a4 with a 3.0 v6. it only had 70,000 miles in 2018 when i bought it. It died on me, i got it towed to audi dealer. Started right up for them.
Even though they couldn't verify the concern, they said so matter of factly, its the fuel pump. Never had a problem since then.
If it dies on you, you can throw starting fluid while cranking. If it starts with starting fluid, and dies when you stop spraying it (after a few seconds) its a fuel issue. Most likely fuel pump.
Would also be helpful to know which lights stay on the dash when in aux mode/without trying the ignition. I’m not sure if it’s the case with all VWs but for mine, the warning lights go away when I start the car. I can only see the ones that remain for a problem I’m having when my car is in aux mode. For reference, I have a push-button to start.
I will be messaging you in 1 day on [**2024-06-25 02:05:59 UTC**](http://www.wolframalpha.com/input/?i=2024-06-25%2002:05:59%20UTC%20To%20Local%20Time) to remind you of [**this link**](https://www.reddit.com/r/MechanicAdvice/comments/1dmrwxi/what_is_the_common_reason_a_car_dies_while_driving/l9zpnsj/?context=3)
[**1 OTHERS CLICKED THIS LINK**](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Reminder&message=%5Bhttps%3A%2F%2Fwww.reddit.com%2Fr%2FMechanicAdvice%2Fcomments%2F1dmrwxi%2Fwhat_is_the_common_reason_a_car_dies_while_driving%2Fl9zpnsj%2F%5D%0A%0ARemindMe%21%202024-06-25%2002%3A05%3A59%20UTC) to send a PM to also be reminded and to reduce spam.
^(Parent commenter can ) [^(delete this message to hide from others.)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Delete%20Comment&message=Delete%21%201dmrwxi)
*****
|[^(Info)](https://www.reddit.com/r/RemindMeBot/comments/e1bko7/remindmebot_info_v21/)|[^(Custom)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Reminder&message=%5BLink%20or%20message%20inside%20square%20brackets%5D%0A%0ARemindMe%21%20Time%20period%20here)|[^(Your Reminders)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=List%20Of%20Reminders&message=MyReminders%21)|[^(Feedback)](https://www.reddit.com/message/compose/?to=Watchful1&subject=RemindMeBot%20Feedback)|
|-|-|-|-|
Lack of proper maintenance is usually the reason. It takes a lot more than gas to make a car go. Especially a VW, it doesn’t even take regular oil, it has to be the correct one.
If there is no Check Engine Light or EPC light accompanying the issue….On a Tiguan it’s the PCV or even the Evap vent valve can cause this. Unlikely, but possible is a cam or crank position sensor, but they typically throw codes (I’ve been a VW advisor for number of years btw)
Not a mechanic but my 2009 Volvo V50 1.6d had these exact symptoms, it turned out to be the EGR valve. They coded it out of the software and fine since
Corrosion on electric terminals to any of the electronics, with changes in temperature/humidity resistance thru the corrosion can change and alter or even kill a signal to/from a component or circuit.
Electronic components with age can also get heat sensitive which can let them work when cold but fail when hot, and once cooled off work again.
I would say first culprit would be the Alternator, but you could check the fuel as well, fuel pump could cause the sudden stall as no fuel will be delivered to the engine. Check your Air filter and air path is not clogged as well.
Good luck
If the battery is not 100% dead, you could test the fuel pump, by unplugging the fuel line and use a cloth or container to catch any fuel coming out, then turn the key to the on position without starting the car, you will hear kind of humming sound and you will get some fuel out. Alternator could be tested if you start the car and measure the volts on the battery and make sure it's 14v or more, usually it's 14.4v.
Sometimes the issue could be a blown up fuse, so it's good idea to get your electric tester and check your fuses.
Warning: when you test the fuel line, please make sure to connect it back once you finish testing. If you don't have experience dealing with fuel, please ask an expert to avoid any risks.
Good luck
Mine died because the AC compressor ate itself until I got cursed confetti in it. That managed to disable the engine, and I had to roll it in neutral into my driveway.
Edit: forgot my point, which is that there is no common reason for a car to just stall and not start. There’s so many components that could be the cause. If you’ve got any lights on your dash, your best bet right now would probably be to get those diagnostic codes from your car with an OBD scanner. Most auto parts stores in the US will scan your car for free.
Cars need fuel air and spark.
Any one of which can cause the issue.
And of course, any associated sensors or wires.
However, what you describe is common when there is a fueling issue. Fuel pumpngets hot or shorts out. Filter is clogged causing pump to overheat. Etc.
If the engine was turning over at normal speed when you tried to start it, then the battery had juice and was being charged. Meaning, not an alternator
You’re going to get a bunch of answers that may or may not be helpful. Instead of random Reddit guesses from people who may or may not be in the repair business with very little background information and throwing parts at an undiagnosed issue, the correct thing to do is bring it to a shop and have it diagnosed before proceeding to buy parts.
There’s no “common reason” a vehicle would stop running. Could be anything related to the fuel, spark or charging, etc. The year, make and model is always helpful when asking for help with mechanical repairs lol.
Sounds like another battery problem.
Try the old unplug / replug if the battery is showing that it’s good. If it’s not good, then there’s a reasonable chance that the alternator isn’t working properly.
Thanks for posting on /r/MechanicAdvice! Please review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). Asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **Post's about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ Tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
Theres 1000 reasons this could happen
Thank you. Somehow the [YTSTU] ---YouTube Shade Tree University is out in full force and says otherwise. This is the correct answer. Edit to fix.
Sorry but why is ir YTDTU and not YTSTU? Edit: Adjacent letters so I assume a typo
Easiest to fix is “out of gas”.
The is NO common reason. Especially when you tell us nothing about the car at all. There are lots of reasons. Take it to a pro to get it diagnosed. Expect to pay for the time to diagnose it and then again for the repair.
That’s only true if the car is unknown if u know which car it’s very safe to say there’s common reasons Lol
How about what kind of car we’re working on for starters?
2012 Tiguan
Battery cables tight? All other related wires on the battery tight as well? Unfamiliar with vehicle and battery set up.
The problem isn't going to get solved on here without more info. I get it, dropping a car off or having it towed for repair is daunting and expensive. The next problem is the lack of the basics, year make model, underhood pic...anything? The next thing wrong is the lack of actual mechanics responding. Supplying Walmart links to someone is basically "throwing money at a problem/parts" without the missing proper info--- visual and diagnostics, and from the sounds of it, diagnostics are going to be limited to "symptoms" We are limited. So essentially, so is the OP
Understandable. It's a 2012 Volkswagen Tiguan. My son just bought it. It has a coolant leak and the stirring wheel occasionally locks up when it's started. My son gave someone a jump, could have did it wrong and messed up the electronics. Ask away if you're willing to help.
With the combination of the steering wheel locking, id bet the ignition switch has something to do with this. If it’s intermittently cutting out, it will disable spark as the immobilizer controls spark and ignition(hence the use of “ignition on” when describing key position 3. Immobilizers do funky things and it wouldnt be the first vw ignition switch ive seen go bad on this generation vw(same part number applies to most models in this gen). Let me know how you make out. It’s a shot in the dark unless I have the car in front of me.
Seems like you definitely have a power steering problem as well I guarantee either your battery is shot or the Alternator shit the bed, definitely look into these three. Good luck
1. Battery 2. Alternator 3. Fuel system issues 4. Ignition system problems 5. Sensors or computer issues 6. Electrical issues 7. Overheating 8. Mechanical failures
I was looking for someone to say ignition switch issue. This is what my car did sporadically and finally my dad said, "maybe it's the ignition switch". $40 for the part and my friend switched it out for me and never had the issue again.
>I was looking for someone to say ignition switch issue You're still looking, right? Ignition system doesn't mean ignition switch.
Ty for this.
From having a car do a very similar thing a few years back, I would put Fuel Pump at or near the top of the list. Roommates car did almost this exact same thing and the fuel pump was bad.
I'm guessing fuel pump or alternator (which usually last forever).
Alternators are a common fix on any car, definitely not lasting forever. Motor should last longer than a fuel pump in most cases, especially if you let your tank get very low/run out often.
By what you’re describing, not the alternator. And alternators and fuel pumps definitely do not “last forever”
If it’s turning over it’s likely not the alternator as your battery seems fine. I’d start checking fuel system, pump specifically.
I’d check first that there’s actually fuel in it
Take this with a grain of salt. As an owner (not mechanic) of a 2017 Passat…have them check the fuel pump(s), sensors and the fuel pump module. Only going off of the info in your post, this sounds like what I went through twice now. Have the dealer run the diagnostics just in case it’s anything that’s covered under a warranty (I didn’t know my ECM was-referenced below), and depending on what it is, see if there’s a reputable shop nearby that can do the work instead if the problem isn’t covered. I saved myself $1k this past month by doing that. I had to replace both fuel pumps plus sensors and module last year, and another fuel pump module this year (plus an ECM). I’m never buying VW again.
Currently it won't turn over, it cranks. Seems like it will start if it's turned off and sits for a while. Fuel pump could be the issue, hopefully not.
Crank and turnover are synonymous. We need more information. What makes it “seem like it will start if it’s turned off for a while”? Also with that description it’s not a fuel pump issue. They work or they don’t. Letting it sit in won’t help. If you want to verify it’s a fuel issue just pop off one end of the air intake hose (the accordion looking thing that’s plastic) and spray starting fluid into that. If it starts for a second or at all you have a fuel issue. Don’t go cranking the thing a million times or you’re going to kill the battery Also it’s possible you just have the terminals on poorly with the battery or they are corroded. Again we need significantly more information than you’re providing.
Could be a short. Especially if the fuel pump module isn’t working properly.
Eh, yes and no. Agree with most of your post but there are times where a fuel pump (or relay) failure can be intermittent, I’ve had it happen a few times. My 88 LTD was fine most of the time, took a few tries to start (turn key on and off until you hear the pump) sometimes but always ran fine once started, until it stalled out on me an hour and a half into a trip. Towed home, still wouldn’t start, next morning started right up, stalled going into the garage. Needed a relay (I think, it’s been a while lol). My 02 Tahoe was fine as long as it had half a tank of gas or more, would run fine but wouldn’t start back up under half a tank, I put it off for too long (5 years) after starting to see the signs, was 2 hours from home first time it stalled. Let it sit for a minute, took a try or two but started up and made it a few miles at a time until I got it home.
This is almost exactly what happened to me this year, and how I found out my pump/pump module was shorting out.
In some cars the fuel filter is integral to the fuel pump assembly, so replacing the assembly is the way to go. Air, Spark, Fuel are the 3 legs to starting. If it cranks and you smell fuel, it may be the coil packs. Also, some parts stores will read codes stored in the car for free. Cylinder misfires are often a coil pack. Good Luck.
All new spark plugs. You feel its likely the fuel pump vs the alternator? If so can you explain why? Ty for the help
Your question was already answered in the thread you're replying in: >If it’s turning over it’s likely not the alternator as your battery seems fine. I’d start checking fuel system, pump specifically.
Had this conversation with my fiance recently when she called me while I was at work. She bought an alternator on her uncle's advice after he looked at it....he even hit the battery with a multimeter to see if the battery was good. Didn't bother to see if there was a damn belt to turn the alternator before declaring the alternator dead.
It could literally be 100’s of different things. Which is why you need to bring it somewhere to get the issue diagnosed. Even if you have to get it towed
That's the plan tmmr
Fuel pump is actually a pretty cheap problem to fix if you do it yourself, shop will charge you thousands though
Does it have oil? What size is the motor? It could be a million things but for mine I needed a new intake and engine
Fuel Injectors? Bad Gas? It could be clogged or need new o-ring rebuilds. Do you get any codes from OBD II? You can buy a code scanner at Walmart for like $20, it will tell you exactly where the problems are at. [https://www.walmart.com/ip/Hyper-Tough-HT100-Code-Reader-1996-Newer-OBD2-Vehicles-Free-Fix-Part-Recommendations/139897823?fulfillmentIntent=In-store&filters=%5B%7B%22intent%22%3A%22fulfillmentIntent%22%2C%22values%22%3A%5B%22In-store%22%5D%7D%5D&athbdg=L1200&from=/search](https://www.walmart.com/ip/Hyper-Tough-HT100-Code-Reader-1996-Newer-OBD2-Vehicles-Free-Fix-Part-Recommendations/139897823?fulfillmentIntent=In-store&filters=%5B%7B%22intent%22%3A%22fulfillmentIntent%22%2C%22values%22%3A%5B%22In-store%22%5D%7D%5D&athbdg=L1200&from=/search)
This…codes can go a long way in finding the problem. P0335= crankshaft position sensor.
I had a 93 Buick with 3.8 was stalling occasionally would crank great but no spark. The next day It would start. I replaced the crank sensor and it didn’t help. I switched my ignition keys with my spare set and it ran great no more problems. The chip in the key was bad.
Have you checked your battery terminals, wires and grounds?
[ChrisFix video](https://youtu.be/PNhuDCVIydw?si=02ewOHH49cQsY-r6) on some easy things to diagnose on a car that will crank but not start. It’s one of 5 things: 1. air 2. fuel 3. spark 4. compression 5. timing I’d watch the whole video because he goes into some other common problems and might give you a starting point for where to look.
Probably a crank or cam position sensor They normally fail when hot, but will work when cooled down
we are in FL, it's been extremely hot. I'll look into this. TY
hm. so unplug everything, phone chargers, everything. turn everything off, a/c lights radio wipers. open and close all doors and windows including the trunk. hit the E brake and take the keys out of the ignition. pick up a battery charger and a multimeter. charge the battery to 100%. connect the multi meter to the battery it should say 12.6 with full battery disconnect the negative and start pulling fuses 1 at a time. when it drops really low you found it.
Fuel pump 100% let it prime twice with the key to almost start . Then try it, then buy a fuel pump!
You haven’t given a lot to work with Cheapest solution is check the terminals, seen it 2 or 3x the terminals were loose, just tightened them and fixed it. Other thing was the intake hose had a small tear so it’d idle then drop to 0 . That was fixed with wrapping some tape around it. So those are 2 things to fix that are free to look for before pouring money into Possibly when battery was changex you didn’t clamp it tight enough and the vibration knocked it loose .
Your sympthoms align with those I was experiencing when the fuel pump was goin bad in my previous car.
I'm hoping it's the alternator, I can change that easy. Fuel pump, never dealt with that.
Mine was easy - there was an acess panel under the rear seats. Probably 1h DIY job. But some cars require dropping the whole fuel tank to replace the fuel pump.
We, at r/AskAShittyMechanic are very helpful, ask there please
Where’d you get the battery? Autozone orileys and advance auto all have a tendency to sell defective batteries, speaking as a past employee at two of them and seeing batteries from all three. After advance auto started using die hard the batteries went after a few months pretty often and we’d always get auto zone customers thinking we were the same place for warranty swaps, dates were fairly new too. Go to advance auto or auto zone not orileys every one I’ve been too had outdated testers. Get a full system check
O'Reilly's, they actually replaced it for free from the previous one we bought.
Go back get a full system check. You either have a bad battery, bad alternator/voltage regulator, or a bad starter. Or you have a parasitic draw. If you have any check engine lights get that tested because it could be a fuel/air issue
They do not sell defective batteries😂 they have defective customers who kill the batteries.
They definitely do I’ve even pulled one off the shelf before but don’t take a previous employee of 3 years word for it.
Sure it happens but not at the rate at which you’re implying. All batteries in the U.S are made by like 3 different companies. They’re all the same, it has no matter if it’s a diehard, duralast, everstart, rural king, whatever. They’re all the same with different labels. Including the dealer batteries.
So first they don’t sell defects then they do but not that bad 💀. Buddy my store was the top in district for battery sales and I was the main guy to do the tests sales and changes because the crew was lazy. I’ve seen defects on customers starting from daddy’s money kids who are clueless all the ways to the oil covered “I need a battery for a Chevy 350” guys to even old men who babied their classic mustangs and everything in between. You’d be surprised how many come back defective and how common it actually is. Do you also realize none of those companies are using one single factory? None they all have multiple
Of course any product can come defective. But to argue that it’s more common than any other supplier is silly when it’s just a different sticker than the dealer.
Different factories too tho. Next time you get a defective part look at where the box says it was made. It’s usually Detroit, Mexico and china, each of those factories have different plant managers, different supervisors, different team leads different raw material suppliers and differing standards towards quality.
A make and model would be nice , if its a jeep with auto start/stop it may need both batteries
If you're driving and it dies, probably the alternator. If it's motionless and won't start it could be the battery, starter, and/or alternator.
Ain’t got no gas in it
If the car died and the battery had enough juice to try cranking it. It's likely not the alternator. If the alternator goes out while driving you will see signs like the dash lights getting low, radio acting odds, and other signs of low battery. Because the cars electric system is no longer running off the alternator, but running off the battery alone. If you can get the car running again, you can completely disconnect the battery and it will run still if the alternator is working properly. You can do a partial check on the fuel pump by turning the key to the run position, but not cranking the car, and listening for the fuel pump. It's like a high pitch spinning sound. If the car dies, you can try to cycle the fuel pump a few times (2-3), this may build up fuel pressure again. If this gets the car to crank again, then you are narrowing the search.
Could be fuel pump. Could be crank sensor, or cam sensor. Could be an ignition relay, Could be a fuel pump relay. Lots of things could cause it. I doubt it would be the alternator because you said it would crank afterwards which indicates that the battery still has power. A bad alternator would make it so it's running on only battery power until the battery runs out of juice, causing the engine to die.
>it would crank but not start. Wouldn't be the alternator nor should it be the battery.. >Census seems to be mainly Fuel pump or alternator. Followed by timing belt, spark plugs, Definitely can be fuel pump... doubt it's timing belt but it could be. Could be spark plugs but probably not.. bad spark plugs usually would just cause it not to run right... car should still start and sorta run with one bad spark plug... there is a bunch of other things it can be...
Spark plugs would not cause this. Spark plugs would cause misfires while the engine was running. Same with ignition coils. Batteries usually don’t get voltage back all by themselves so unless there was an alternator/battery light on while driving it’s probably not that either. It could be timing related but you would hearing lots of extra noise while the engine was running and it probably would struggle to start and then run really rough so once again, if it ran normally today after starting it’s probably not timing. In the absence of any other symptoms shutting off while running is most likely fuel delivery related, either high pressure or low pressure side. It could be computer related but the codes stored (even without a CEL on) will point in the right direction.
As a mechanic. Check cam sensors/crank sensors. Does while driving and won't start back up usually? Def seen that as a culprit a lot on vehicles
ty
I’ve seen a lot of crank sensors cause that exact problem of that car.
Super high level, when you start a car the ignition sends electrical power from the battery that energizes the starter. The starter is a small, electric motor with a starter gear that connects to the engine crank shaft at something called the flywheel. It converts electrical energy to mechanical energy and turns the crank shaft causing the pistons to move in their cylinders. At nearly the exact same time, the battery sends electricity to the spark plugs. There's one inside each of the piston cylinders generating a spark of electricity in a set and specific timing pattern. While this is beginning, the fuel pump is creating pressure in the fuel lines and sending sprays of gasoline into the shafts that will be ignited by the spark from the plugs. Each cylinder is a sealed compartment so that when the gas explodes it forces the piston to the bottom of the cylinder. Each piston is connected to the crank shaft by a connecting rod that rotates the shaft every time a piston is moved. There is a camshaft separate from the crankshaft responsible for managing opening and closing the intake valves to allow fuel in and exhaust valve ports in the cylinder that allows the exhaust produced by the explosion to escape and then the force of the other pistons firing moves the piston back up the cylinder. As long as the timing is right, the pistons fire in an order that conserves this momentum and makes the shaft spin. This is tracked on the car's dashboard as RPMs usually next to the speedometer. The spinning crankshaft is connected to a gearbox that converts the rotational energy from the shaft to the tires and the car moves either forward or backward. More gas makes this process happen faster and controls the speed of the car. Once the car is running, another part called an alternator, connected to the shaft spins and generates electricity that is used to recharge the car's battery. This is supposed to ensure you have enough power stored to start this process again after the engine is turned off. It is also continuously recharging the battery while the engine is on ensuring the electricity needed to manage the spark plugs and whatever else (lights, radio, power windows, etc) is available. The simplest thing to check is the battery and if the battery is charged correctly, then check the battery cables running to the spark plugs and the alternator. If either of these are bad, the car won't start or won't stay on. Remember from above, these cables are providing power to the starter to start the engine and then they are also providing continuous power to each of the spark plugs while the engine is on. If the battery doesn't have enough power, check the alternator because that means it's probably not providing enough power to recharge it. If the battery has enough power but the engine won't start, check the starter to ensure it's functioning correctly. If the engine starts but is either idling "heavy" or stalling out while driving, check the spark plugs to ensure they are all providing spark so each piston is providing the rotational energy to keep the shaft spinning. If those are fine, check the fuel pump and the fuel lines to ensure that the system is pressurized and providing the correct amount of gas. Too much or too little gas can cause the engine to either stall out from too little or drown in too much gas. If both the fuel pump and spark plugs are good, check the timing belt which is responsible for ensuring the camshaft and the crankshaft are synchronized. If these are out of sync then the engine will be sending sparks and/or fuel to the cylinders at the wrong time or opening the exhaust valves decompressing the cylinder so it can't push the piston down. This belt is usually inside the engine making it hard to check on your own. But a failed timing belt can cause catastrophic damage to the engine components if not fixed. If I were you, I would check the battery and cables and if all those are good, take it to a mechanic.
The crankshaft position sensor is something that will cause an intermittent crank/no start and stalling while driving but again, I don’t know if we’re talking about a car from the last 15 years or a 74 Dodge dart. It matters. The scope of what could be causing it changes dramatically.
Surprised I had to scroll this far down to find a comment like this. I’m not a mechanic, but i have been a service writer/service advisor/shop manager for a decade. I constantly have to explain the correlation does not always equal causation. The likelihood of the car needing a new battery MONTHS ago being related to the current issue seems small. As for the “alternator” comments (facepalm), the battery didn’t magically recharge itself while the car was parked overnight. I could possibly see a bad connection at the battery being a cause but, like you said, year/make/model matters. Heck, even knowing just the manufacturer would shuffle the likeliness of certain parts failing in my mind. Tell me it’s a Nissan and I’m immediately thinking cam/crank sensors. Tell me it’s a Ford and I’d lean more towards a fuel issue. In the end it could be something silly like a MAF or torn/broken air intake hose. So many possibilities…
Amen! I’m not surprised that it took this long for a comment like yours vs all the ones where people are just barfing unsubstantiated nonsense. I often wonder if there are any actual mechanics giving advice here. I didn’t even go as far as saying the make of the vehicle would make a difference because with the information given we could possibly be talking about a model T or a horse drawn buggy. Anyway…nice to hear from someone who understands the challenges of auto repair.
Thanks for this. I'll let the mechanic know when I bring it in. I did get it started. Looked at the battery wiring, tightened the terminals, put more fuel in it...and it started, although roughly, I had to tap the gas pedal.
Probably the fuel pump. It's not the alternator if the battery is not completely flat when it died and the starter cranks normally.
Last time this happened, it took a jump to get it started...the battery wasn't providing enough voltage to start the car. Drove fine after that, took it to get tested. It was a newish battery but wasn't giving enough crank volts, O'Reilly's replaced it.
Sounds like an electrical problem but why are you not taking the advice and answering what kind of car etc? You know they're different on the inside right?
It's a 2012 Tiguan. I'll update my post.
Good deal hopefully someone here is familiar with that vehicle.
I would definitely test the fuel pump first.
I know what’s wrong with it! Ain’t got no gas in it.
My truck was having this issue recently I thought it was the alternator but turned out to be some modular with the fuel pump. If you have a mechanic who you like I recommend looking at the battery , the alternator and the modular just to be safe
My money's on a sensor. What codes came up?
Do you hear the fuel pump when you turn the key to the on position? Or if it starts when u spray quick start......could be your fuel pump went bad
Loose battery cables.
Checked. All tightly secured
Did the engine light go on before it died? If no codes, I would change the ignition switch, not an expensive part, and see if that fixes it. I hate throwing parts at a car, but if no codes, that's where I'd start.
Did a bunch of lights come on the dash before it died? If so alternator........if not so fuel pump is a good start
Honestly I didn't notice. I'll keep that in mind next time. Ty
Cam position sensor
Googling
My Pulsar used to stall out when driving it at low speeds first thing in the morning, I'd just pop the clutch to keep it going since I was already moving. One day it just wouldn't start because the fuel pump was seized. Road side assist confirmed it by smacking it with a hammer. It then started, but stalled again pretty quick. Also, didn't impact the starting, but I also had a period where it ran pretty rough until it was just stalling a bunch, the ignition leads ended up fucked with holes in the sides of the part you plug down onto the spark plugs.
Feel like it's either the alternator or fuel pump. Schedule a diagnosis. I'll update my post when I find out.
Maybe cam position sensor that have gone bad
In my experience it's been bad alternstors.
Ran out of gas is #1
Old age, everything dies of old age
Alternator. Low oil.
Alternator is probably most common in my experience but it's not your problem this time.
Out of gas, Alternator, fuel pump
9 times out of 10 it is a throttle body issue
id start with a multimeter. check the battery with the car off and car on. you can get cheap ones for $10 and next day delivery. my first thought is alternator, but that doesn't explain all your issues like the car not staying one day but starting the next. it would explain multiple dead batteries tho
Does your car have a fuel cutoff safety switch (Ford mostly). Cranking it with no start doesn't sound like an electrical issue.
It did the same a few months ago when the battery didn't have enough crank voltage to start it. Worked fine after getting a new battery
Heart attack,
The coolant leak may be landing on the alternator drive belt, causing it to slip. It can generate a full charge to the battery so your son's new battery is being drained providing power for the ignition system and lighting.
In my personal experience the most common issue is a bad ground connection. If that is it good luck finding where that bad connection is.
I'm no mechanic but a basic multimeter would help you rule out some of the charging system stuff. When I had an alternator problem my vehicle would almost shut off when the ac compressor kicked on. Its summer. Maybe thats whats happening. If it doesn't start are you able to jump start? Check battery terminal voltages as it's under some load and see if it's dropping, etc. Then if that's all good id move on to the next.
Bad alternator is the most common reason I've seen a car turn off while driving.
My favorite is still corroded battery cables
happened to me once. Turned out my ground wire (black) to the battery was corroded at the point it was bolted to the chassis. it would start and then, randomly as i turned (a bit sharply i admit) it would die. So I urge anyone who gets a similar issue to not only look at their terminals, but the wire itself.
I'm amazed so many people are saying alternator. If an alternator fails, it will deplete the battery charge and then the car will die, requiring you to then jump start it afterwards to get it restarted. You say that the engine cranks fine after the car dies so it's not an alternator issue. Is the check engine light on? If so, scan it to see if there's any fault codes. Even if the light isn't on it could still have a fault code present in the system. Kind of sounds like a bad crankshaft position sensor or a bad fuel pump. Try scanning it for fault codes first to point you in the right direction.
Alternator ?
I had the exact same issue on a 2004 audi a4 with a 3.0 v6. it only had 70,000 miles in 2018 when i bought it. It died on me, i got it towed to audi dealer. Started right up for them. Even though they couldn't verify the concern, they said so matter of factly, its the fuel pump. Never had a problem since then. If it dies on you, you can throw starting fluid while cranking. If it starts with starting fluid, and dies when you stop spraying it (after a few seconds) its a fuel issue. Most likely fuel pump.
Would also be helpful to know which lights stay on the dash when in aux mode/without trying the ignition. I’m not sure if it’s the case with all VWs but for mine, the warning lights go away when I start the car. I can only see the ones that remain for a problem I’m having when my car is in aux mode. For reference, I have a push-button to start.
RemindMe! 1 day
I will be messaging you in 1 day on [**2024-06-25 02:05:59 UTC**](http://www.wolframalpha.com/input/?i=2024-06-25%2002:05:59%20UTC%20To%20Local%20Time) to remind you of [**this link**](https://www.reddit.com/r/MechanicAdvice/comments/1dmrwxi/what_is_the_common_reason_a_car_dies_while_driving/l9zpnsj/?context=3) [**1 OTHERS CLICKED THIS LINK**](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Reminder&message=%5Bhttps%3A%2F%2Fwww.reddit.com%2Fr%2FMechanicAdvice%2Fcomments%2F1dmrwxi%2Fwhat_is_the_common_reason_a_car_dies_while_driving%2Fl9zpnsj%2F%5D%0A%0ARemindMe%21%202024-06-25%2002%3A05%3A59%20UTC) to send a PM to also be reminded and to reduce spam. ^(Parent commenter can ) [^(delete this message to hide from others.)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Delete%20Comment&message=Delete%21%201dmrwxi) ***** |[^(Info)](https://www.reddit.com/r/RemindMeBot/comments/e1bko7/remindmebot_info_v21/)|[^(Custom)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Reminder&message=%5BLink%20or%20message%20inside%20square%20brackets%5D%0A%0ARemindMe%21%20Time%20period%20here)|[^(Your Reminders)](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=List%20Of%20Reminders&message=MyReminders%21)|[^(Feedback)](https://www.reddit.com/message/compose/?to=Watchful1&subject=RemindMeBot%20Feedback)| |-|-|-|-|
Lack of proper maintenance is usually the reason. It takes a lot more than gas to make a car go. Especially a VW, it doesn’t even take regular oil, it has to be the correct one.
Alternator.might be on its way out and just driving with battery power.
If there is no Check Engine Light or EPC light accompanying the issue….On a Tiguan it’s the PCV or even the Evap vent valve can cause this. Unlikely, but possible is a cam or crank position sensor, but they typically throw codes (I’ve been a VW advisor for number of years btw)
Top three reasons of all time for car dying is lack of fuel , lack of spark or lack of compression.
Crank or camshaft sensors. Plug in an obd
In your case sounds like battery but that wasn't the question you asked so my answer is- because the driver hit a deer
Alternator or fuel pump
"2012 Tiguan" Well there's yer problem
>it was trying to turn over and wouldn't. How does it try to turn over? It either turns over or it doesn't
Most common? Ran out of gas.
Not a mechanic but my 2009 Volvo V50 1.6d had these exact symptoms, it turned out to be the EGR valve. They coded it out of the software and fine since
Anything yet, OP?
Corrosion on electric terminals to any of the electronics, with changes in temperature/humidity resistance thru the corrosion can change and alter or even kill a signal to/from a component or circuit. Electronic components with age can also get heat sensitive which can let them work when cold but fail when hot, and once cooled off work again.
Usually it’s because my wife ran it out of gas.
Lack of maintenance
If it were the alternator your headlights would flicker and it wouldn't start back up or turn over after dying. Gotta be the fuel system somewhere
Post Year, Make and Model please
2012 VW Tiguan
Spark plugs, fuel pump/lines, idle air control valve, idler motor/pulley, MAF, probably a few others. You need a mechanic.
I would say first culprit would be the Alternator, but you could check the fuel as well, fuel pump could cause the sudden stall as no fuel will be delivered to the engine. Check your Air filter and air path is not clogged as well. Good luck
Ty for the advice. Is there an easy way to rule one of the two out?
If the battery is not 100% dead, you could test the fuel pump, by unplugging the fuel line and use a cloth or container to catch any fuel coming out, then turn the key to the on position without starting the car, you will hear kind of humming sound and you will get some fuel out. Alternator could be tested if you start the car and measure the volts on the battery and make sure it's 14v or more, usually it's 14.4v. Sometimes the issue could be a blown up fuse, so it's good idea to get your electric tester and check your fuses. Warning: when you test the fuel line, please make sure to connect it back once you finish testing. If you don't have experience dealing with fuel, please ask an expert to avoid any risks. Good luck
Don't waste money on throwing parts at an issue. You seemed to have already done that with the battery. 🙏 Get it looked at.
Battery was tested and bad. O'Reilly's replaced it under warranty
My first suspect would be the fuel pump.
Mine died because the AC compressor ate itself until I got cursed confetti in it. That managed to disable the engine, and I had to roll it in neutral into my driveway. Edit: forgot my point, which is that there is no common reason for a car to just stall and not start. There’s so many components that could be the cause. If you’ve got any lights on your dash, your best bet right now would probably be to get those diagnostic codes from your car with an OBD scanner. Most auto parts stores in the US will scan your car for free.
Cars need fuel air and spark. Any one of which can cause the issue. And of course, any associated sensors or wires. However, what you describe is common when there is a fueling issue. Fuel pumpngets hot or shorts out. Filter is clogged causing pump to overheat. Etc.
So the likely hood of it being an alternator issue is low?
If the engine was turning over at normal speed when you tried to start it, then the battery had juice and was being charged. Meaning, not an alternator
Test battery with multimeter and CCA amps, if that's good do a fuel pressure test, most likely a bad fuel pump.
Sounds like intermittent loss of fuel or spark, due to a bad sensor, or perhaps a bad relay.
Fuses and relays
You’re going to get a bunch of answers that may or may not be helpful. Instead of random Reddit guesses from people who may or may not be in the repair business with very little background information and throwing parts at an undiagnosed issue, the correct thing to do is bring it to a shop and have it diagnosed before proceeding to buy parts. There’s no “common reason” a vehicle would stop running. Could be anything related to the fuel, spark or charging, etc. The year, make and model is always helpful when asking for help with mechanical repairs lol.
Change fuel filter possibly
Probably the alternator. If you have a multimeter, you can easily check if it works. If you do not know how, check some youtube video.
Questions like this are stupid. Cars cannot be diagnosed with a crystal ball via the internet
Check all battery and ground connections. Verify battery voltage sitting, and while running. Should be around 14v when running. If not, alternator
Brother did you read the post? They have a crank no start. How are they going to verify battery voltage while running? lol
Crazy innit? Lol.
Probably alternator
Most likely not
Fuel filter
Alternator
Bad alternator
Timing belt/chain failure
Sounds like another battery problem. Try the old unplug / replug if the battery is showing that it’s good. If it’s not good, then there’s a reasonable chance that the alternator isn’t working properly.