I recently bought a 2013 Volvo s60 from a dealership. Right after I got the car I started having a consistent misfire with one cylinder and coolant leaks. At one point I did have white smoke coming out of my exhaust so i was almost entirely positive it was the head gasket. My mechanic took my engine completely apart and found a brand new head gasket, water pump, and timing belt. My mechanic had reported that whoever changed these parts before I got the car had majorly screwed up when putting it back together. He rebuilt the engine correctly and we hoped that it would fix the problem. I am no longer seeing white smoke or abnormal exhaust, however my coolant does go from max to min levels in about a month still and I still have a misfire on one cylinder head. Both me and my mechanic are pretty stumped. Does anyone have an explanation for the issues with my car?

 

Some Volvo engines (the 04-07 r engines) are known to crack cylinders - causing a problem such as that. Also I worked on an early s40 with the 4cyl variant of that engine that had a cracked cylinder - I'm guess from when it was overheated.

Examine in the cylinder that continues to misfire with a bore scope - is the piston and plug cleaner than the other cylinders? (that would be an indication of coolant intrusion)

You might also pressure test the cooling system overnight when the engine is cold - and see if you can create the misfire, or find coolant in a cylinder the next day.

Or use a combustion gas detector on the cooling system with the engine running.

 

Thank you, I will look into that.