gas getting in the oil on 1991 Volvo 940

what could be the cause of gas getting into the oil? Had the oil changed 1 week ago and it's showing about a quart over full now, unmistakably gas in there. What could it be? TIA.

by in Athens, AL on May 18, 2010
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1 answer 3 comments
ANSWER by , May 19, 2010
I would check your fuel pressure, the fuel pressure regulators go bad on these engines causing very high fuel pressure, which will flood the engine. Many times it will run relatively well and you may not notice, but you may see black smoke from the tailpipe and some driveability issues. Do you have a check engine light on or any symptoms?
COMMENT by , May 20, 2010
thanks bretb. Turns out it was a thermal sensor.
COMMENT by , May 21, 2010
Oh, the coolant temperature sensor failed, I've seen that a few times too. Did you have an issue with the engine being hard to start after it was warmed up?
COMMENT by , May 21, 2010
Didnt have a problem with that. It idled rough though and sputtered badly going up a hill. Smoked black at times too. Seems alright now. Appreciate the feedback.