So, I was hoping someone could explain the reasons for my recent problem with my intake manifold/gaskets. I drive a 2001 SS with about 88,000 miles. Here is the history...

About two years ago, I had the intake manifold and related gaskets/seals replaced due to apparent corrosion from the coolant. I have a take home car for work, so I rarely drive my Monte, probably less than 15,000 miles since the intake work was done. It was explained to me the corrosion is a preventable problem so long as you get a coolant flush every 2 years or so.

Well, two years go by, and I find my car overheating and misfiring, and discover it is the same leaky manifold/gaskets problem again. I had everything replaced again, but I'm a little upset about this happening again so soon. I hadn't gotten a coolant flush yet, but it was right around the two year mark and I didn't think a few weeks would make that much of a difference.

I'm wondering if anyone could give me a good explanation as to why this would have happened again so soon, and if there is anything I can do to prevent it from happening again. Should I be getting coolant flushes more often? Is the fact I don't drive the car very often a factor? Any other thoughts at all?

 

wait, so you got all the gaskets replaced again but kept the same coolant?

 

My own comentary on coolant destorying gaskets.... I feel that is more "myth". People have a belief that DexCool is 100% responsible for destroying the lower intake gaskets. I think it may promote or increase damage to the gaskets, but I don't believe it's the cause. The stock gaskets are made from nylon, and I don't think the nylon holds up well to the heat and chemical reaction from ANY coolant. My "case study" is my 3100 equiped Grand Am. When I bought it, it had the green coolant in it, around 90K, changed the nylon gaskets. At 180K, I was changing head gaskets and when I popped the lower intake off, the nylon gaskets I put in was cracking apart again. In my ownership, this car has NEVER ran Dex of any kinda (just the green stuff). If you get close to 100K miles on nylon gaskets you're doing pretty good.

NOW, as for the problem of about 15K miles on new gaskets having them go bad, I can only make speculation. Perhaps they were not properly seated during installation and cracked, perhaps a slight mis-manufacture of the gasket. Do you know what brand gastets were put in?

Today, if you are having lower intake gaskets changed, go for the aluminum lower intake gaskets!! This should give you much better life on the gaskets.

 

Lower Intake Manifold could have been upgraded to the metal version the first time.

Perhaps everything wasn't bolted down properly, gasket surfaces cleaned completely, etc.

 

Go for the aluminum lower intake gaskets..The nylon gaskets crack from heat.,The aluminum gaskets cost more than nylon gaskets ..

 

Maybe improperly torqued upper / lower intake mounting bolts (tightened too much) that caused the gasket(s) to fail early? Having just done this job myself recently, I was surprised how lightly the upper bolts are torqued.

 

Obviously the coolant was replaced each time the gaskets/manifold were replaced. What I was trying to say is that I didn't get a chance to do the recommended coolant flush before the problem came up a second time, and was trying to figure out if that was a contributing factor, despite the fact it hadn't been that long and the car hadn't been driven much.

Thanks for the replies. Doesn't really change my situation seeing as how I have already had the work done, but I appreciate the help anyway.

 

Dont purchase another GM product....they are all crap! Your leakage problems will be solved!

 

Sparky...the upper intake bolts are only torqued to 10 pounds because the intake is a composit plastic part....Chances are if the bolts are tightened too much then the plastic will either crack or break allowing coolant or oil to leak out...If GM wasnt too concerned about saving money on their builds and make a bigger profit...then they would have installed a cast aluminum upper intake with quality gaskets such as Felpro and you wouldnt have these problems! Also...if the plastic coolant tubes which run coolant through your belt tensioner into the lower intake (Very stupid design by the way) were made of brass or aluminum...they would last much longer without having to be replaced but the design of these coolant tubes going through the belt tensioner is the dumbest thing i ever saw in engine design!

 

Agree. Especially with the plastic tubes running coolant through the belt tensioner assembly. That little piece of @$#% coming off the back of the lower intake manifold caused me no end of grief when I was trying to re-install the manifold. And the other one was so brittle it basically disintegrated when I touched it. Can't believe it was actually still operational at that point.