Lately, I've had some issues. I know its cold and all, but after the engine is fully warmed up, and say I'm stopped somewhere at idle, I'll get bouncing RPMs. At first I thought spark plugs, but then I noticed something else.... Say I go to a store real quick (~5-10 mins) and come out. (short enough for the engine to still be warm) I turn the car on and the coolant temp gague points to about two slots to the right of normal operating temp (the middle) then once I start driving goes to the left, in the middle where its supposed to be.


Solution...: Coolant Temp. Sensor? Seems kind of obvious, but I just want to double check. Would this fix the bouncing RPMs too?