Intake Manifold Gaskets

[icechopper26]

I just replaced my intake gasket on a 99 GMC Suburban, 5.7L Vortec 89K miles. From my observations of the failed gasket, it is not a question of IF this will happen to your vehicle but WHEN you will have to replace it.

The first sign of problem with my vehicle started with an oil change and the burnt/rusty looking residue on my oil filler cap. No evidence of cooling system fluid in the crankcase, just the smelly residue. With less than two hundred miles past this reference point I found reddish drops of fluid at the bottom of my transmission bellhousing. Shit, I thought, a front seal leak on the transmission, but it was actually coolant. One hundred miles later I check the oil again and find the level perfect but the unmistakable smell and residue of coolant on my oil filler cap. I jumped onto THE FORUM and found a huge amount of information which indicated an intake manifold gasket leak.

I was VERY lucky to escape without servere engine damage. My vehicle ran flawlessly throughout this process and I had both an internal and external leak.

Once the engine was disassembled and the gaskets were removed, it was obvious why this is happening. The plastic base of this gasket is designed to hold the neoprene gasket material in the proper locations. In reality, the plastic base fails over time and allows the neoprene material to wander, causing leaks. It appeared to me that the neoprene material was not broken down nor failed by caustic coolant as speculated by other's opinions. This gasket material appeared still pliable but solid.

If you have the 96 through 99 5.7L engine in your vehicle or a vehicle you are thinking of purchasing, you will be replacing these gaskets if they haven't been replaced already. Read The Forum, check for signs of gasket failures often to find the first indicators of a problem.

[wafrederick]

I found out 2 or 3 weeks ago,Fel-Pro has come out with updated intake Manifold gaskets for the Vortec 350 and 4.3.The updated ones are made out of metal instead of plastic.I have seen one,a Jasper rep that comes into my father's shop brought one in for a sample.The updated ones are about $67.00 a set and are the better ones.Jasper threw away every plastic intake manifold gasket set that they had and replace them with the metal ones in each gasket set included with the engine.If you have to replace intake gaskets on a vortec 350,loook into the updated intake gaskets from Fel-Pro that are the metal ones

[ukimok]

In case it helps anyone. I just had this and one other symptom was that my temp gauge would suddenly go crazy and peg to the right and then a few seconds later go back down to normal. Also check gauges light would intermittently come on.

[wafrederick]

If you have to replace intake gaskets on a Vortec 350,get the updated intake gaskets from Fel-Pro and most auto parts stores that sell Fel-Pro gaskets should have the updated intake gaskets in stock.

[NoEcm]

Originally Posted by wafrederick

If you have to replace intake gaskets on a Vortec 350,get the updated intake gaskets from Fel-Pro and most auto parts stores that sell Fel-Pro gaskets should have the updated intake gaskets in stock.

Do you have a Fel-Pro part number for these gaskets? Are they newer than part # MS98000T?

[wafrederick]

I believe that is the part number and ask if that is the part number from any autoparts stores.I do believe that most auto parts stores now sell the updated intake gaskets now.