About 3000 miles ago I replaced all the intake seals on my ’91 Formula 350. The o-ring seal on each stem and the rubber one with the piece of metal banding around it on all the intake valves. I did all that because it was smoking so badly at start up. It’s doing it again! I have seen other posts on here and it sounds like this is a problem with TPI engines. I realize its not really hurting anything, but it looks awful to start a car and see smoke. How long should the seals last? They were from the GM dealer. Did I get the wrong ones or is 3000 miles about right. Any help would be appreciated. Thanks.

Chris

 

It has nothig to do with TPI as such.

The best ones to use are the Teflon ones, like you can get from Comp and Crane and others. Unfortunately they require cutting the valve guide to some specific size. The rubber kind aren't as good. The OE type use the most inferior materials.

Look for ones made of Viton, instead of Neoprene like the GM ones. The GM ones are about like OE shocks: just good enough to make it through the test drive long enough so somebody will buy the car, and that's about it.

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