idle speed to fast

I have a 2001 Alero. Recently the idle speed has crept up to about 1500 rpm at idle in park. In the mornings when it has sat all night it sometimes goes to 2000 rpm on start. This has gone on for 4 to 6 weeks with no other affect to the car. Runs fine at highway speed and shuts off normally. In the last week the transmission has started to shift harder from first to second, sometimes going to 4000 rpm before the shift. Had car hooked up to a scan tool... didn't show anything. Could these two problems be related to one thing? or just a coincidence? I would take a solution to either problem or both. Thanks

Clean the mass air flow sensor. It is probably dirty and sending the wrong signal to the computer causing it to idle too fast. You can clean it yourself using electronics cleaner just be very gentle and allow it to dry before replacing it. This should also cure the shifting problem.

like GTP dad said, deffinately a bad MAF. If cleaning doesn't do it, the MAF electronics themselves may even be bad - in which case replacing the entire MAF would solve the issue - anywhere from 20$ to 45$ depending on where you get it. By the way, welcome to the forum.

ok, replaced idle control motor and cold air intake sensor. Since it is a 2.4 it has a map sensor rather than a maf sensor. replaced that this morning and still the same... any other sugestions?

bump

I have a 2000 Alero and I too have a fast idle issue. I've taken it to the dealer and they can't figure it out, but what's new with that. Excuse my ignorance, but where is the Mass Airflow sensor and what does it look like?
TIA

I have a 2000 Alero and I too have a fast idle issue. I've taken it to the dealer and they can't figure it out, but what's new with that. Excuse my ignorance, but where is the Mass Airflow sensor and what does it look like?
TIA

Sorry but this thread is too old. Please start a new post with your problem and be sure to indicate whether you have a 2.4L or 3.4L engine.

Thread closed.