My car smokes during start up (most probably valve seals) but it also starts smoking profusely when you just leave it to idle for prolonged periods of time (like 20-30 minutes). If you drive it and then let it idle periodically (i.e. Mcdonalds drive through), no smoke comes out.

If it's just the valve seals, I'll go with Vortec heads..if it's the piston rings..I'll go for an engine swap (expensive).

I need info for the next big thing. Thanks.

 

Do a compression check, if a cylinder comes up low on compression you either have bad rings or pistons or both

 

So will good compression indicate that my piston rings are alright eventhough I have bad valve seals?

 

If you get low compression on one cylindar, then squirt a few drops of oil in the cylindar. If the compression goes up then that means that your rings are goin bad, if the compression stays the same that means you have a burnt valve, blown head gasket, etc.

 

Wouldn't a leakdown test be more revealing?

Also, with compression test, the cylinders must come out to about the same within 10% of each other.