QuestionHi there Roger!
I just purchased a supposedly PERFECT, well maintained, 1 owner, 90,000 miles 4 Door Volvo SL 240 sedan, and I'm having a litte trouble. My dad used to be a volvo mechanic, and he couldn't quite figure out what's up, so here are the clues:
It misfires. Not always, but only when it warms up, and not every time. When it starts to misfire (hesitate), the smell of the exhaust changes to a more fuely smell. Once the problem starts, it does not go back to correct function until you've turned the car off and let it cool.
Possibly related: The thermostat on the dash was working until it reached the middle, then would drop back to zero once the car was warm, and usually that would coincide with the other problem. However. I seem to have fixed the thermostat by applying dialectric grease to the plug located under and in front of the spark plugs - I don't know what that plug is called, but it's a plastic-tipped plug that goes to a metal socket. I also applied electric tape to be sure the connection wasn't being hindered, and since then, my thermostat works, but the problem still occurs.
The spark plugs and spark plug cables are fairly new, and the distributer cap/cables and the coil have all been checked for problems.
One thing that might make a difference is that the air-filter compartment has a hole that i need to fix. Also, I recently drove the car through a pretty deep puddle, and it's possible that water may have shorted something out. Also, my muffler is doing it's best to fall off, but it's haphazardly held there, all together, but the car-end of the actual muffler part's connection to the tube that goes to the engine is corroded, and allows the tube and the muffler to rub against eachother, which causes a rattling sound.
Once the car starts hesitating, besides the strong exhaust smell, it feels a little like i have to give it more gas to get anywhere. It hesitates also when it is in neutral.
I apologize for being long winded, but I want to be as thorough as possible. Other than the listed info, the car is clean and seems like it should be good for the long run, if we can just figure out what's going on. Thanks a lot!
AnswerIm surprised your dad didnt figure this one out. This sounds like a temp sensor problem or a fuel pressure regulator that is being stubborn. Sounds like an overfueling issue. How is the wiring harness? If its original then I would be searching for a new one. We can go further if you want. Roger
