In a previous post I mentioned that my 94 940 with a Mitsubishi turbo would on occasion stall out when slowing below 20 mph. This would followed by a brief rumbling sound when decelerating (like marbles in a can) coming from the location of the turbo. This noise has gradually increased in duration and intensity in recent weeks.
`Now the car stumbles a bit in the morning when cold and for a few moments there is some white smoke and unburned fuel smell. I also checked the antifreeze after sitting over night and there is considerable pressure being released from the radiator cap.
One post recommended releasing the pressure when cold and restart it for 15 seconds. If pressure develops that would be an indicator. I tried this several different times with no pressure developing. BUT wouldn't a cracked head leak more likely when its hot?
The radiator and water pump was replaced 6,000 miles ago at 109,000 miles, so I also have to consider it has been overheated as well. The final nail in this scenario?
Since I believe there are water lines going to the turbo, could this pressure be caused by exhaust leaking into the cooling system via the turbo?
I'm having a trusted mechanic run the codes and do a leak down test. Is there anything else I should check in the interim or add to his list?