Hi, I have a 1992 Mazda b2600i with 217,000 miles. It's ran perfectly up to now, but the other day, it started up and ran on 3 cylinders. I cleaned/gapped the sparkplugs and it ran fine until I took it on the highway and it started running on 3 again, smoking all over. When I got it home, there was smoke coming out of the engine bay. Yesterday, I took the heat shield off of the exhaust manifold and started it up. It ran on 3 again, but eventually started running on 4 cylinders; however, it continued smoking long after it was running correctly and didn't stop. The smoke is a very white smoke, not blue like burning oil. I have a feeling that I blew a head gasket inside of the engine, resulting in the missing and the white smoke is from burning radiatior fluid. Does anyone have any idea of what the problem may be, how fluid got on top of the exhaust manifold underneath the head shield, or any other insight?

Thanks,
Efrem

 

You are probably right ,it sounds like a head gasket.Although you can run engine until atoperating temp then shut off and let it cool.Remove all spark plugs andcrank engine over to see which cylindersblow coolant from spark plug hole.This will let you know for sure.