I have a 87 L98 tpi iroc with 59k miles on it. Recently we did valve stem seals on the motor due to a puff of smoke when a warm startup was performed. Now, it appears to be slightly smoking at idle and it puffs smoke when idling at a stop and starting accelerating. This only happens when the engine is warm, if its cold there is no smoke. What gives? Valve guides? Ring? Where do you start to diagnose a corrective action?


#1 do a compression check?
#2 pull heads if #1 is ok? Do full valve job? or new heads?


Note, the car doesn't smoke when accelerating or getting off a hard acceleration and it doesn't smoke when its cold. Only when its hot.

 

The first step would be to see what color the smoke is and if there is any strong smell coming from the exhaust. That will give you an idea of what kind of leak you have causing the smoke and how to go about fixing it.

 

Pretty sure its oil... Just wondering if its worth pulling heads and doing a full job on them or buying new? Also, ill do compression checks on cylinders, what psi should they be at? What difference in psi would reflect a problem?

 

Should be around 145psi on all cylinders. If you have low compression and it's burning oil then it sounds like the piston rings are no good.


As for the heads, they're not the greatest but they work pretty well on a stock setup. Unless you want to get into having a new tune on the ECU I would stick with stock heads.