ok here's whats going on, i have a 88 firebird with a 305 fi engine after about 20 min of running i get white smoke coming from my exhaust, i checked the engine oil and it's clean no antifreeze mixed in it so it's not the headgasket, the engine runs very quiet and doesn't over heat at all now could this be the valve stem seals have gone bad? or could it be trans fluid getting into the engine thru a bad modulator valve? the smoke smells like burnt oil,lmk what you guys think it is




jack

 

valve seals would be a puff of smoke on startup and clear up as the engine warms up Id try a compression check to make sure the rings are sealing.

 

There's not always antifreeze in the oil with a blown headgasket, that's just one of the symptoms. Do a compression check like HF monster stated. When you do the compression check, make sure all cylinders (or at least the whole side you're working on) has the spark plugs removed. It helps when testing for gaps between cylinders.

 

How odd, I have a 91 camaro with a 305 tbi, low miles in my opinion,88,000..have had it off the road for 8 years now and just got it back on the road...had to fix few minor things, window motor, heater core, etc but otherwise runs great..but yesterday as i was attempting to fix my a/c..my car also started just belching white smoke..i've had my share of oil burners but this doesnt smell the same..i drive it foir a bit and it seems to clear up, but when you stop at idle it starts up again..hope I'm not hijacking your post but will follow it to see if you get any answers..

just wonderin..could it possibly be fuel related..Just realized my smoke started after i had just filled up?

 

my buddys truck is doing that and it has a cracked head. so may be your cause. when his is cold. everything is perfect, but as he drives it more white smoke comes out.