Engine Performance problem
1998 Volvo XC70 6 cyl All Wheel Drive Automatic 76,000 miles
At random, unpredictable intervals the car will die. Most typically it occurs when you stop the car with the engine idling such as at a stop light or sign, or in stop and go traffic. It has also died while maintaining speed on the expressway and the engine RPMs will fluctuate wildly and then the engine dies. Hitting the gas doesn't effect the RPMS but can sometimes be kept running if I shift into neutral and play with the gas pedal. All of this occurs randomly---sometimes when the engine is cold, sometimes after it's warmed up for 30 minutes or more. Some days it runs fine without incident, while other days chronic problems. Other times the car will have problems for a while and then run fine for a long period of time. Weather doesn't seem to be a factor and, of course, none of this happens when the mechanic has the car.
The fuel filter and fuel pump relay have been replaced, and the mechanic has been driving the car for 4 or 5 days now with a fuel pump pressure gauge, but none of the symptoms show them selves.
I take it they have scanned for codes and nothing was stored? If that is the case I would start with replacing the idle air control valve and removing the throttle body to clean out.
June, 25, 2009 AT 6:11 PM
They did that first. Codes pointed to the turbo but we didn't believe it. Turned out to be the MAF. Just replaced it and the car runs fine.
June, 27, 2009 AT 11:38 AM
Thanks for keeping me updated to the fix. I am surprise the faulty MAF sensor did not cause a fuel trim code to set but they do also cause problems stalling with out even setting a code.
July, 25, 2009 AT 5:23 PM
I had some problems with surges and the engine trying to die! It stalled a couple of times at slow speeds. I found the " winter" button was stuck on, therefore trying to take off in third gear or so! Nice easy fix.I do love this car, though!