erickles

Hi, I have a 2003 Forester 2.5X with over 100,000 miles on it. It is a manual shift. Whenever I am in slow traffic and I am using clutch control to crawl along, or have stopped and am idling, the RPM's start to climb. I can be stopped with no foot on the pedals and the RPM's could be racing up to 2500 sometimes higher. Or I could have the clutch down and be in first gear and again the RPM's race this high. It only seems to happen in hot weather. I took it to the dealership and they have no clue what it can be. Any ideas?