94 Chevy Silverado Smokes when started

[mabowens]

I have a 94 Chevy Silverado that emits blue smoke when started after sitting overnight. Any ideas what causes this and how I can fix it? Thanks guys

[heavyredchevy]

I have this same problem. Its probably your valve seals. What happens is over a period of time your valve seals get worn out causing them to leak oil into the combustion chamber, in doing so, the engine will produce a blue smoke for a couple of seconds after start up. You should take your heads off and rebuild them.

[2000CAYukon]

This is due to the fact that GM only used a single o-ring as a valve seal on the exhaust valve. The o-ring dries out and cracks, then blue smoke at startup.

The valve seals can be replaced without removing the head. You need a valve spring compressor for this job. Compressed air to hold the valves in place makes it a little easier; although, it can be done without compressed air.

Felpro makes a premium exhaust valve seal that is better than the stock o-ring. I have a complete set of valve seals, new springs (you would not reinstall 100K+ mile valve springs) and rockers in the garage. I had shoulder surgery that has taken longer to heal than expected. Once it is better I hope to knock out the valve seals on my 90 K1500 5.7.

//2000CAYukon

[jveik]

a classic smallblock problem...

[roadrunner_70]

Check out this old thread. You might find it interesting.http://www.automotiveforums.com/vbul...ht=Valve+seals