Hello All: I need some help and advice. I bought a 1990 Buick Lesabre 4 years ago.Bought it from a junk yard. It was sold to junk yard with a rod knocking. I'm assuming they put another motor in it. Anyway it'* run perfectly for the 4 years I've had it, but a week ago it started missing while I was headed home from work, and kept going dead upon stopping at stop signs (especially hot day), later that day I drove it again, and it was running perfect again, but was blowing small amount of white exhaust smoke, so I panicked and parked it. It does not have water in oil, no bubbling in radiator, not overheating. So, I'm wondering what could the problem be? I've driven it (around the block) a couple times, still runs perfectly, BUT still has the white smoke. I'm kinda afraid to put it in the shop, afraid they'll tell me it'* a blown head gasket, and want 1400.00-1600.00 to repair. Is there anything I can check myself to figure out what it is, BTW it'* the 3800 motor.

Have you checked the coolant level to see if any has been consumed? You will want to confirm the engine actually is ingesting coolant before you freak out about the engine ingesting coolant.

The 3800 engine doesn't pop a head gasket for the sole reason of popping a head gasket. If they do fail, it is usually a result of catastrophic overheating, and even then, the risk of losing a head gasket is about the same as cracking a head or other severe damage.

If it is for sure coolant, I would start by checking the throttle body gasket. Also there could be a leak between the intake manifold and heads, but that tends to dump coolant in to the crankcase, which you have already checked.

If it is not consuming coolant, you may want to check out the catalytic converter. Your symptoms could be consistent with a broken/plugged unit. You can whack it with a rubber mallet when cold to see if it rattles, which will confirm it'* broken.

Thanks a lot for your reply. the car hasn't used any coolant at all (I went ahead and changed anti- freeze anyway). Will check the catalytic converter first thing tomorrow. I'll also check throttle body gasket, it couldn't hurt to change it out anyway.

Had this happen to me. Check the transmission modulator, ruptured seal sucking trans fluid into engine.

Just a refresher......

Usually white is coolant.....

Blue is oil.......

Black is a rich fuel condition......

Light grey is transmission fluid.....as grandpabuick stated, pull the vac line off the modulator, and if you see tranny fluid, that'* your problem.....

Thanks a lot, will try that! I'm going to go ahead and try a block test also.

I believe it is a light gray color, I'm going to try that tomorrow, also have a guy going to loan me his block tester to try. Thanks for the advice.