3.1 V6 Question

1997 Pontiac Grand Am SE

I heard that the 3.1L engines have a defect in the intake gaskets. Something about the size of them. I heard this from some older mechanics who hate anything made after 1976, but is there any truth to this?

I have a Buick with a 3.8L which I love. How reliable are the 3.1L engines? I noticed it only has one cooling fan. Are these engines known for over heating, or are the prone to any particular failure I should be made aware of?

I guess I'm asking for the pros and cons of the power train of a 1997 Grand Am.

Thanks All

Problems are: LIM gaskets (mixing oil and coolant), engine do get hot very fast but do not overheat that is why on newer models GM decided to squeeze another electrical fan (maybe separate fan for condenser). Also for some reason this engines misfire on #3 and #4 cylinders, but they are Ok in general.

I noticed the engine warmed up pretty quickly. But if that's normal than I wont worry to much about it. I still may look into adding another electric fan. Now, what exactly is a LIM gasket? Is it a head gasket? And is there anything that can be done to prevent the LIM gasket from failing?

If your Lower Intake manifold(LIM) gakets are before 2003 then they are the old style and will eventually leak.

I have seen a couple different leaks either coolant in the oil or oil in the coolant.
You could have neither of those and the gasket leaks into a cylinder(s), which will cause a misfire on occations and can eat up the valves.

You can do a cylinder compression test and usually find if the head gaskets are bad.

Hope that helps.

So basically if the LIM gasket developed a leak anytime after 2003 and were replaced I wouldn't need to worry about the LIM gasket anymore? Is there anyway to tell if I have the new style or the old style gasket? And how difficult is a LIM gasket repair?

Yes they should be if they were replaced in 2003 +.
Thier is no way to know without pulling the LIM ,
though the new design has metal around the openings.

Its not to difficult, try this link......
http://www.automotiveforums.com/vbulletin/showthread.php?t=688030

When the lower intake gasket went out on mine I only got an external leak of coolant. The gasket was plastic with a rubber type core, the plastic split causing the leak. I think it would have lasted longer but the car had a few overheating problems before this happened.

It went at 169k, what a fun task it is to change.

The link in the original message you linked to isnt working?

Yes they do leak externally especially under the TB and on the oposite end of the intake by the alternator and power steering pump.

Can leak if you dont use enough rtv sealant too on the corners where the intake meets the heads/block.

I am working on one now, which only had 31k on it, overheated, collapsed two pistons (overheated). These engines are known for piston slap. The only warning I had was a loud lifter like noise which I could not detect from any one cylinder, compression was fine in all cylinders. a word of caution, it is getting extremely hard to find pistons and rings unless you go to a dealer $$$$$$$

parts are available in most parts stores like Napa.

Not really, tried NAPA stores, autozone, about 20 web sites, murrays, etc with no luck, some sold pistons, could not get rings, some sold rings, could not get pistons, was not a easy chore to track down. Some sites, like autopartsgiant.com tried to sell pistons and rings, but once you look at the specs, the rings would not fit the pistons, they finally agreed and told be the rings were not available, autozone sells pistons but could not sell rings, go figure that one out, I did find them, ended up having to replace all 6 instead of 2.

must be your geographic local because I have had trouble finding anything ,,,,, :dunno:

It just makes sense though replacing them all insted of just one.
It would suck to just have replaced the two then after its all back together find out that another was damaged and having to tear it all back down would be a PITA ! :lol:

Oh yea something else that I forgot, rings are often sold oversized then you must measure and cut them to fit.
Measure 3x cut once :thumbsup: