Why does engine rev to 2600 Rpm's at start up?
Why Does My Car Engine Rev Up In Neutral & Sound As Though It Wants To Turn Over & Switch On?
If your using your air, a big stereo or anything that draws power from your battery your alternator will kick in to charge your battery. this will cause the engine to rev up a little. You will hear a little noise from the engine. I hope that's all it is .