I have a 01 Sunfire GT with 130,000 km's on it. Over the past few days I've noticed that when I start the car something in the engine is making a revving or surging sound.

The tach is not showing any change in RPM during this time which makes me believe it's something else. Any ideas?

Thanks,

I should add:

The car drives fine otherwise, acceleration is ok, car does not surge any other time.

So an update on the condition:

Only happens when the car is "cold".... does not occur if the car has been driven then left for even a few hours. Has to be left either all day or over night for problem to re-occur.

The tach itself goes up/down by roughly 200 rpm, I know its normal to idle a bit higher when the car is warming up, but it has never varied like this before.

Car otherwise is still running fine, took it on the highway and everything is fine.

clean the idle air control valve and throttle body and report back

IAC probably.




PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

I'll pull it and clean it.. if it reoccurs then I will replace.