My mysterious volvo 850

I believe my head gasket is blown, but nooone reallly knows what’s wrong with it…car stalled & then smoke came out the oil tank an coolant tank an muffler I just got this car used a month ago… an none of the boys have any idea where to start… I need some advice & priced out parts

A mechanic can tell you for sure whether the head gasket is kaput or not. They have a variety of tests they can do which will tell you one way or the other. Find a good inde mechanic and ask for a diagnosis on the head gasket. That’s the first place to start.

Just for kicks check the pcv valve.

There’s no way to provide a definitive answer to your questions.

If the car was overheating and it got hot enough to blow a head gasket i would run a dry compression test first followed up by a wet compression test. The latter will give an indication of whether piston rings are damaged; and they often are on an overheated engine. This test will not work on a head gasket breach into a cylinder but will reveal whether any alleged good cylinders are really any good.

This is what makes changing a head gasket only a very iffy proposition. Money is expended doing the head gasket and then it may be found that the entire engine has gone south.