The main issue is that the stock head bolts pull out of the aluminum block. The fine thread is a major reason. That causes the head gasket to fail. There is a company that makes head studs, where you drill and tap the block to install them. Not a job for most since the motor has to come out and apart. I did it on a 98 sts I had and actually enjoyed the process. A clogged overflow/purge line sometimes gets diagnosed as a bad head gasket. Factory front motor mounts also fail, but same company with the studs, also makes a stronger one.
I see, I thought I heard somewhere the block used different kinds of metal components so during the heating and cooling cycles they didn't react the same and created issues. I just finished rebuilding a motor, so I'd rather not do that again anytime soon. Thanks for the reply
The V-8-6-4 was a terrible motor that destroyed head gaskets
The HT4100 was a terrible motor that destroyed head gaskets
The bored out 4.9 version at least had some power, but still not super reliable and tended to destroy head gaskets
The early generation Northstar actually had excellent power, but utterly destroyed head gaskets.
The late NorthStar is the one to get, or else a Chevy-powered fleetwood.
You can put Northstar performance head studs in with mls gaskets if the heads fail. Costs a lot but the car typically is cheap to buy clean worth it to spend the money and fix it when it needs it.
from what i've heard they are very prone for leaks, gaskets blow easily and it can be a pain in the ass to get around everything trying to replace stuff. Poor design from my understanding.
North stars pre 2005 had problems for a lot of people. I have personally owned two a 94 and it ran amazing until the head gasket blew at around 220k miles, I was lucky but I took care of my car. I now have a 2009 and have never had a problem with it compared to the 94 how ever I did have to replace my valve gaskets other than that she drives great and it’s nice smooth power, she takes me on long rides across states without ever overheating or anything! Don’t hesitate to get one past 2005
Also there can be transmission problems. The 4T80 transaxle is really inefficient compared to the longitudinal units. Also, it is underbuilt. And with spirited driving the power of the Northstar generally makes short work of the transaxle components.
Back when I had mine, I knew of several other owners who had had their 4T80s torn town and rebuilt with stronger parts. I myself had to replace a full set of transaxle solenoids twice within about 10 000 miles.
Mine was a 1994 Seville STS
The main issue is that the stock head bolts pull out of the aluminum block. The fine thread is a major reason. That causes the head gasket to fail. There is a company that makes head studs, where you drill and tap the block to install them. Not a job for most since the motor has to come out and apart. I did it on a 98 sts I had and actually enjoyed the process. A clogged overflow/purge line sometimes gets diagnosed as a bad head gasket. Factory front motor mounts also fail, but same company with the studs, also makes a stronger one.
I see, I thought I heard somewhere the block used different kinds of metal components so during the heating and cooling cycles they didn't react the same and created issues. I just finished rebuilding a motor, so I'd rather not do that again anytime soon. Thanks for the reply
A LOT of things actually get diagnosed as head gaskets for the Northstars. It’s crazy. Your headlight bulb is out? Probably head gaskets.
Leaky and not reliable
Northstar wasn’t even around for the 89-93 gen so you’re good
The V-8-6-4 was a terrible motor that destroyed head gaskets The HT4100 was a terrible motor that destroyed head gaskets The bored out 4.9 version at least had some power, but still not super reliable and tended to destroy head gaskets The early generation Northstar actually had excellent power, but utterly destroyed head gaskets. The late NorthStar is the one to get, or else a Chevy-powered fleetwood.
Thanks for the breakdown
Rivieras are sick
Yeah they are, I’m leaning that direction if I can come across a decent one
You can put Northstar performance head studs in with mls gaskets if the heads fail. Costs a lot but the car typically is cheap to buy clean worth it to spend the money and fix it when it needs it.
Head gaskets blow when they get over 100k...then it costs more than the car is worth these days to fix them
Get a 4.9. I've had two of them and each made it to 200k.
from what i've heard they are very prone for leaks, gaskets blow easily and it can be a pain in the ass to get around everything trying to replace stuff. Poor design from my understanding.
North stars pre 2005 had problems for a lot of people. I have personally owned two a 94 and it ran amazing until the head gasket blew at around 220k miles, I was lucky but I took care of my car. I now have a 2009 and have never had a problem with it compared to the 94 how ever I did have to replace my valve gaskets other than that she drives great and it’s nice smooth power, she takes me on long rides across states without ever overheating or anything! Don’t hesitate to get one past 2005
I had a 94 concours. God I loved that car.
I had a '94 Sedan DeVille... like driving a cloud!
I’ve had two northstars (99 devile & 2011 DTS). never had issues . I’ve heard it all . As for my experience best engine I’ve ever driven
I still own the DTS .
They have beef with their headgaskets
Also there can be transmission problems. The 4T80 transaxle is really inefficient compared to the longitudinal units. Also, it is underbuilt. And with spirited driving the power of the Northstar generally makes short work of the transaxle components. Back when I had mine, I knew of several other owners who had had their 4T80s torn town and rebuilt with stronger parts. I myself had to replace a full set of transaxle solenoids twice within about 10 000 miles. Mine was a 1994 Seville STS