unknown gasket

[Criminal_Mind]

I have a 97 grand am with a 3.1

I have a leak in the coolant behind the thermostat. Standing in fron tof the car. the thermostat is on my right. I put my hand under the thermostat housing and then go BACK PAST THAT. It is not the thermostat housing that is leaking. I can feel some kind of rubbery gasket that is coming out or has blown out and this is where the leaking is coming from. I don't know what the part is that has the gasket or the gasket name. I would appreciate if anyone knows what the hell I am talking about to give me the name of that gasket and the part that it goes to. It looks like I am going to have to take off the intake and throttle body at the very least. I don't have an exploded view of the engine, if I did it would make it alot easier, does anyone also know where I can find an exloded view of the engine? I have a Chilton manual for the car but oddly it doesn't have this gasket anywhere that I can find, nor does it have an exloded view of the engine. Please help.

[MantaGreen97]

LOL "unknown" haha, funny...

Three letters you should get acustomed to hearing regarding any of the Gen III 60 degree engines...

L... I... M... (Lower Intake Manifold)

Sounds very much like a LIM leak to me. Very common and very frustrating problem with these engines. Very clearly an engineering flaw, one that was never entirely fixed up until the 3900 LZ9/LZ8 engines. So that's from like 1994 up until 2005 maybe? GM has faced and is facing a few class actions over this, but it seems they always seem to "get away" from any responsibility.

Gasket re-design and proper threadlocker on the intake bolts, have minimised re-occurence of the problem on the affected engines.

Do a search for LIM and you'll see tons of hits. Find angrysk8r's thread in the How-To Articles section, for your repair instructions ;)

[rixGAphx]

It's leaking coolant, not oil, correct?

That's the end of the LIM gasket, where it is sandwiched between the LIM and the head.
There shouldn't be anything 'rubbery' there.

The silicone rubber should be just a *little* forward of that, directly under the T-stat housing, where the LIM mates to the horizontal 'web' across the 'Vee' between the front and rear cylinder banks.
That rubber oozes out a bit when the LIM is installed. It seals the oil/oil vapor inside the 'Vee'; there shouldn't be any water/coolant there (unless it dribbled down from the head/LIM interface.

Hope this helps,
-Rick

[daman]

^^ yup,

Sounds like the silicone gasket maker you use on the block
in between the two heads is leaking at the corners.

start tearing into it....:(

[beavercountyemt]

and make sure u use angrysk8ter's (sp) teardown thread to do it. It's better than a chiltons. I just did mine a couple of weeks ago in about 10 hours. you'll feel like :banghead: while your doing it but it's satisfying when u get it done and the car starts up. Have fun with it and good luck

[RazorDX]

Had to do this on my Dad's Lumina, and it's coming up on my brother's. Damn you, 3100 and your craptastic gaskets.

[daman]

Do it right with the right gaskets and you'll do it once.

[Criminal_Mind]

Thanks for the responses guys. I looked over the how to and though it does look like a pain in the butt, I'm going to do it myself instead of taking it in to a mechanic. Thanks again.

[daman]

You can do it it's not a bad job just take your time.