Have a guy who was asking me about doing a head gasket on his 3.1. I know these things are notorious for the LIM gasket going bad and overheating. What is the best way to differentiate between a head gasket or LIM gasket? Is a compression test the best way to decide? Going to look at the car later this week so need some help figuring it out so I can help him get it fixed.
Thanks
If it's an older 3.1 they don't have quite the problem with the lower intake gaskets that the newer 3100's do.
A compression test could help identify a BHG. But at the same time, going to do the heads you'll be taking both the upper and lower intakes off anyways. So once you get down to the LIM if you find the gasket all blown to hell, then you'll know that's your problem.
One thing to note though. Stupid people will have the LIM gaskets blow, then overheat the engine. They'll just drive forever with the temp needle on the H and not even notice, then they'll take out the HG as well.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
SHOoff wrote:If it's an older 3.1 they don't have quite the problem with the lower intake gaskets that the newer 3100's do.
A compression test could help identify a BHG. But at the same time, going to do the heads you'll be taking both the upper and lower intakes off anyways. So once you get down to the LIM if you find the gasket all blown to hell, then you'll know that's your problem.
One thing to note though. Stupid people will have the LIM gaskets blow, then overheat the engine. They'll just drive forever with the temp needle on the H and not even notice, then they'll take out the HG as well.
Lower intake usually doesn't go bad. These engines are built like takes. My 2.8 had 175,000 miles on it when I pulled it for an nine swap. Only thing I replaced was alternator and starter on it after 100,000 miles beside plugs, oil, and wires.
On the inside my car looks like a fighter jet.
We did LIMs on my friends 3400 Monte is about 4 hours in my apartment complex parking lot. Given we have some experience doing them between the three of us. But its definitely not a bad job.
Once youre down to the LIMs youre basically head and exhaust manifold bolts away from the heads coming off.
Compression test is the best way to tell the difference. For example if youre getting 180 psi across all 6 cylinders and white smoke out of the exhaust its probably the LIMs.
