I have an olds 350 in my 1971 Cutlass. It’s all original block and heads. A couple months back my son took it down to the block and had the heads rebuilt. He put it back together with all new gaskets also replacing the thermostat and housing. The car has been running fine until the last couple of days its blowing white smoke out the passenger exhaust. He has checked the coolant which has not mixed with the oil and both look clean. It’s also not losing any coolant or burning any oil. He is not sure why this is happening. We were wondering if anyone has any suggestions as to what to look for.

Thanks

 

Sounds like a head gasket leak admitting coolant into a combustion chamber to me.

Does the smoke smell like antifreeze?

- Eric

 

sounds like a bad head gasket.or even a intake gasket. check the compression on all cylinders first of all.

 

Could also be a leaking transmission vacuum modulator. Burning transmission fluid is also white. The only thing is, I wouldn't expect it to come out only side of a dual exhaust.

 

Exactly. Plus, burning ATF smells like ATF.

- Eric

 

Does it constantly smoke or is it just a puff of white smoke out the exhaust when starting the car while cold? If it is the later then it isn't a head gasket but valve guide seals. However, if your son had the heads rebuilt I would think the machinist would have installed new valve guide seals.

 

would you not see the oil mixed with coolant?

 

try holding a piece of cardboard against the exhaust tip for a short time ...then examine what fluids are on the cardboard...maybe it is steam?

 

You would hope to, but its easy enough to smell it, and if it smells like antifreeze, it's kind if conclusive.

- Eric

 

Not necessarily, depends on where the leak is., however you would see evidence on the park plugs.

 

Yes, the plug in the bad cylinder will be unusually clean.

- Eric