Check levels of coolant in the cooling system reservoir and WITH THE ENGINE
STONE COLD (like after it's been sitting all night), radiator. If low, add
the appropriate coolant.

Then follow the owner's manual to accomplish a full purge of air from the
system. As much as 45 minutes or so will likely be required to get the
radiator fan to come on twice while you're accomplishing the purge
procedure.

The reason air in the cooling system or low coolant may cause revving at
stops etc. is because certain engine control components are cooled by the
cooling system. Inadequate coolant means improper temperature means
out-of-spec-hot electronic components means incorrect engine control.


"Krystyne" > wrote
> My car suddenly started not idling. That is,
> when stopping at red lights the engine kept reving on its own. The RPMs
> kept jumping from 2 to 3 without my putting any pressure on the gas pedal.
> I could hear the engine reving. The temperature gauge was also reading
> hot. This was within a matter of 3-4 mins. Any ideas of what the problem
> could be, as I'm clueless about mechanics. Any help would be greatly
> appreciated.
>