This might be hard to diagnose. I've got a 98 V6 Contour, ~155,000 miles. I've noticed recently while idling it sort of surges up and down, goes +/- 100 RPM constantly. The dash lights also get brighter and dimmer with the RPM.

It starts and runs fine, but I did notice that when I accelerate quickly the battery light will come on briefly.

I don't think my battery would be at fault, I just got it last year IIRC. My guesses are alternator, voltage regulator, or maybe serpentine belt? But would that stuff cause the irregular idle?


98 Contour V6 MTX, T-Red, 150k mi. Pic SVT Dual Exhaust, KKM Intake, Donnely Mirror, Dension DMP3 Player w/80GB of MP3s, Wheelskin 95 F-150 91 Mustang GT 06 Honda Shadow Aero