I just recently changed the valve cover gaskets on my 1992 gmc sierra 1500 2 wheel drive 5.7L and now trucks smoking any ideas? how do I tell if valve cover it siting correctly


Asked by Apr 14, 2013 at 11:58 AM

Question type: Maintenance & Repair

10 Answers


Either some oil dropped on the headers and it will burn off or the new gaskets are leaking. Does the smoke go away after a while? Can you see if fresh oil is pouring out? Did you torque the bolts or did you over tighten them and bend the valve cover?


If it is smoking in the engine compartment then you probably didn't get the gaskets on right. The best way is to make sure you valve covers are clean and dry where the gasket sits, use some weatherstrip adhesive on the metal and a light coat on the gasket, let air dry about a minute then be quick about putting the gasket into place, make sure it is correctly placed on the valve cover, place valve cover face down on a smooth level surface and place a small weight on it just to hold it down, let setup for about an hour then install normally. Do not overtighten.


Also, only use gasket sealant on the side of the new gasket that mates to the valve cover. No sealant on the side that mates to the head. Make sure all the old gasket is removed as well before installing the new ones. HTH. -Jim


i changed it about a week ago and still smoking from tailpipe.. no oil is pouring out no new spots under truck..i did but I think I may have bent the header now that u say that because my buddy was like give it another 1/8 turn and I did and when I did it made a popping noise.. and its ruber gasket no need for sealant


Smoke coming out the tailpipe doesn't have anything to do with a valve cover. Valve covers keep oil inside the engine. Loose and leaking valve covers drip oil on the headers that make smoke under the hood. Smoke out the tail pipe at start up is worn valve guides. Smoke out the tail pipe all the time when running is worn rings. It's a twenty one year old vehicle, you can expect a little smoke. Just add oil so it does not run low. Get more advice before trying to replace or repair a engine this old. It sometimes isn't worth putting a lot of money into it.


ok but it was fine before we changed the valve cover gaskets is what im getting at .. could the smoke be from the valve covers put on wrong .. its not smoking all the time just after truck gets warm and its only on take off when im driving its fine when I come to a stop and go is when it smokes

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ok this is my first vehicle how will I go about taking out the piston rings and putting new in? and about how much will it take to do ?


My guess is that the PCV (positive crankcase ventilation) hoses were not reinstalled correctly. What color is the smoke? Blue is oil. If the PCV system is not working properly it can cause smoke out the tailpipe. Double check to be sure all hoses going to the valve covers are hooked up correctly and clear. HTH. -Jim

I keep having to redo my gaskets. I hope this time will fix it. I think the smoke is coming from oil that leaked out and I didn't clean it off

Hi, woundering if you solved you blue smoke because of the valve cover gasket install? THanks

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