I have a 1990 240 with 300,000K. Very few problems til now. For about 1 month now, the engine temp has been creeping close to the red line but starts to cool down as soon as the t-stat opens. I have been busy and simply haven't gotten around to replacing the t-stat. Yesterday I pushed the pedal to the floor (big hurry) and heard a lot of preignition/pinging. Sounded like something major let loose in the engine. At the same time there was a massive cloud of white smoke forming behind the car. Once the rpm reduced it took a few seconds for the pinging to stop. Then I gently drove it home.
Now when engine is idling there is white smoke steadily coming out of the tailpipe.
Did a compression test and all is fine there. However each cylinder did spit quite a bit of oil out onto my hand and onto the compression tester.
No bubbles appearing in the coolant.
While the engine was idling I removed the oil fill cap and there seems to be a bit of pressure and oil spitting out. I may be wrong but I think this pressure is more than normal.
Any ideas on what the problem is and what the solution is?
Head Gasket? More than that?