How do you check if LIM or HG is the issue?

[hensleya1]

Greetings folks,

We just purchased an older Grand Prix for next to nothing with, what we assumed at the time, a blown HG. I started browsing these forums looking for a good how-to for HG replacement when I began seeing various posts stating that chances are LIM is the issue and not the HG. So what is a good way to check and see which one is the culprit? Or should I just replace everything at once?

For the record I can't remember 100% which engine it has but im pretty certain it is the 3.1. We're going tomorrow to tow it so ill get all the specifics then.

Thanks in advance,

Adam

If you have a 3.1 it is almost certainly the head gasket that has blown.

A 3.8 on the other hand, it is the LIM.

A failure of the other gasket is super-rare on either engine... I've only heard of one 3800 head gasket blown. Every Craigslist 3800-powered car I've ever seen where the seller claimed "head gasket" it was invariably the LIM gasket instead. The symptoms can be similar, though... antifreeze and oil mix and become friends. Not good.