I just bought a used 2002 Saturn SL1 with 57,000 miles and I just noticed that the car idles very rough, at an RPM of about 600-650, like it's going to stall out, when sitting at stop signs or stoplights with the car in Drive. Oddly enough, the idle is smooth when I turn the air conditioner on. I thought this may be due to the fact that turning the AC on increases the car's RPMs by about 50-100. Also, the car does not have a rough idle in Neutral, Park, or Reverse. Once I start driving, I don't notice any other problems. Any idea of what might be causing this? Another mechanic said it might be the top motor mount, but I'm not so sure because the problem only happens when the car is idling. It does not vibrate or shake while driving.
Apr 29, 2009 at 3:57 PM
