98 Stratus 2. L. Car Vibrates Really Bad When Air Conditioner Is On . It Also Idles At 900 Rpm . Someone Told Me That Was Too Low . What Is The Idle Speed Supposed To Be, And Can I Change The Idle Speed Thanks John C My wife just bought it and I am lost when it comes to mechanic work . Thanks

98 Stratus 2. L. Car Vibrates Really Bad When Air Conditioner Is On . It Also Idles At 900 Rpm . Someone Told Me That Was Too Low . What Is The Idle Speed Supposed To Be, And Can I Change The Idle Speed Thanks John C My wife just bought it and I am lost when it comes to mechanic work . Thanks

I usually get a "vibration" i guess you can call it when the A/C kicks in due to badly warn motor mounts. Without the A/C, mine idles just over the 750rpm mark. On cold days or with the A/C its about the same as yours at 900rpm. If its warm with the A/C it usually comes back down to 750rpm at stop lights or when it sits there running. The idle speed is computer controlled and I'm not 100% positive but it can't be changed. I have owned my car since 01 and the idle has always been the same. Mine is stick and have it drop as low as 250ish rpm and come back up. lol

Good luck and hope this helps.

It's all making sense now. about the engine mounts being loose. The motor shakes "more than normal" when cranking. But its especially shakey with a/c on. Thanks for the info.

NP, Glad to help