Originally Posted by 67Elcamino
I have started by 1940 Desoto for what Im guessing in over 10 years. The oil looked fresh and had good even compression readings. Oiled the cylinders and spun a few times before the first start. Car is not overheating but I do notice blowby through the filler neck white smoke from the exhaust.
What would be the best thing to begin testing or doing in order to eliminate this being that the car has sat for so long? Add a cleaner additive and change oil? add a ring sealer thereafter?
Some more info; I added a oil pressure guage and when cold it reads 40 psi once the car warms up it drops to 5-10 psi Is this huge decrease normal?
Any help is appreciated
Marvel Mystery oil has a good track record for unsticking rings and lifters, you might give it a try. But if it has uniform compression readings, the problem might be elsewhere. As long as no water got into the cylinders, the engine should come back to the same condition it was before being parked. But if that condition was worn out, obviously nothing will change that.
Usually white smoke is water. Does the smoke have any odor to it? Could be a leaking head gasket, cracked head or block. Was the engine full of water or coolant? Does it freeze where the car was sitting? Is the coolant contaminated w/oil? ATF will also smoke white but has a distinctive odor. So does antifreeze. Water not so much.
Blue smoke is oil, and black smoke is too much fuel (running rich: stuck or sunk float, needle and seat bad, choke closed).