ruralways

Hello again everybody,

I posted here a month earlier about the debate of getting my intake manifold gasket(IMG) replaced BEFORE it fails catastrophically. My van is a 2000 base model with 149,000 miles on it. I use it for family vacations only. Well, I not only replaced my IMG using 4 new short bolts and 4 new long bolts from the dealer but also replaced my alternator and radiator cap also from the dealer. Along with replacing the coolant with green stuff after a complete flush, the mechanic also replaced the infamous o-ring.

Here's my big dilemma...
When I went to pick up my van the mechanic who worked on it showed me the old parts that he replaced per my request. The IMG was showing signs of wear so this was a good thing that I replaced it when I did. The mechanic does IMG work all week long. He specializes in this type of work. He has replaced hundreds of them throughout the years. He told me that the gaskets are made better now. He proceeded to tell me that they changed the gaskets since last week and now they are made of metal! I was his first IMG that was replaced with metal. Are you kidding me? I was floored!

I'm really concerned that this is yet just another "let's see what this does" on the Felpro's part. This is a Felpro metal gasket. Does anyone else out there have a Felpro metal IMG? The mechanic told me that if I came in last week I would have had the other kind(neoprene type). Then he told me to let him know how it works out(with the new IMG)!!

Please let me know if I should be concerned. Thanks.

Mary Jo

KJRich

I just had mine replaced mine with the metal intake gasket. As far as worrying about it, I say don't. I had the IMG replaced for the first time at 80,000 miles and it now failed again at 130,000 miles. In my opinion, its worth trying the metal gasket. Mine's only been on a couple days though, so I can't tell you if its going to last forever. What I DO know is, if this one doesn't last, the van is going to hit the road. I would have traded it in this time, except they told me about the new metal gasket, which costs over twice as much as the old one, I might add.

__________________
1999 Chevy Venture LS Extended 3.4 V6 Intake Gaskets Replaced
2003 Cavalier LS Sport Coupe, 2.2 Eco, 5 speed Getrag, all black

Glen_T

Don't worry.....the metal is a good thing.

The big issue with a bolted joint design is load loss in the joint. The bolt can loosen or relax, and/or the gasket itself can relax and the result is less load in the joint. If the load loss is great enough, you can get a leak. Heat up and cool down cycles can speed up the load loss.

It is my understanding that the original GM gaskets were plastic carrier style gaskets. This means that the gasket had a rubber sealing bead around the inner edges, but the base gasket, or carrier, was made of plastic. As the joint is tightened, the sealing bead is compressed until the carrier comes into contact with the metal joint. This limits the load on the sealing bead so you do not overcompress it. Because the plastic can still creep or deform over time, you sometimes see metal eyelets in the bolt holes called load limiters. This limits the load or displacement the joint sees. It also allows you to apply more load in the capscrews without overcompressing the sealing bead.

By going to steel, the creep or relaxation of the gasket is drastically reduced. You now have a metal to metal to metal load path and you better "lock down" the joint. So, having a steel carrier is a good deal. The only downside of this arrangement is the possibility of debonding of the rubber sealing bead from the metal base material.

Another way the engineers design in more margin for load loss is the use of longer capscrews. The longer bolts will stretch more (they're like a spring, and the longer the better), and can therefore relax more than a short bolt before you lose load on the seal. Also, threadlocker on the threads of the bolts can prevent the bolts from loosening from vibration.

Hope this helps...one point of interest. All three of the major gasket manufacturers (Dana-Victor Reinz, Fel-Pro, and Elring Klinger) make some variant of the intake manifold gasket for the 3.4L engine and advertise them in their literature. That just shows how many of these fail and how much money is to be made with an aftermarket replacement.

I know many on these forums disagree, but my experience/research tells me that the reason for the gasket failures is due to the gasket design and the load loss issue, and not the DexCool. But probably only GM knows for sure.....Good luck with your van...Glen

ruralways

Here's the update...

Thanks for the suggestions to not worry. I won't. I know Sandy owner of Olsons Gaskets(I might of messed up on the spelling of his name). His gaskets are mostly metal(for older cars). My mechanic(who I trust very much) said that the biggest mistake drivers do is hop in their van and go...more so in the colder temperatures. He suggested that I run the van and let it warm up before taking off.

It's amazing that my original IMG estimate was $600.00 with the old gasket price. I just paid for the job and he only charged me an additional $17.00 even with the new metal gaskets. I love my mechanic...honest and trustworthy. I hope I never have to move! Thanks again for the information. I appreciate it.

Mary Jo