My 2002 Pontiac Grand Prix just began idling high yesterday. The "check engine" light came on and now it also hesitates on acceleration and it wants to "jump" away from me even when I have my foot on the brake. I'm about to roll over 131,000 miles. Can anyone suggest what the likely problem could be?
Country: United StatesMake: PontiacModel: Grand PrixYear: 2002
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
Is this a regular 3.8L or supercharged?
GM Grand Master Technician 2007. 11 years experience.
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Is this a regular 3.8L and have you had a chance to check the codes? Most parts stores do this for free.
Sorry... My computer kicked me out!!!! It is a regular 3.8L
OK, does it happen more when you are on the brake? Have you got the codes checked? Most parts stores do this for free.
Yes, it definitely happens more on the brake. That's when I first noticed it and I can actually feel it "vibrate" in the steering wheel.
Sorry - I keep forgetting to answer: no, I haven't had the codes checked yet.
OK, can you plug the large vacuum line to the brake booster and see if hitting the brakes makes it idle odd? Also does it do this when parked and hitting the brakes?
Well, I'm at work right now so I can't really go out and do anything.
It does it when parked and when on the brakes. Also, don't know if this is related, but my key has started getting stuck in the ignition lately.
Also since yesterday when I put the car in park it doesn't go in to park smoothly, it almost kind of slams into park.
It makes me think the brake booster is leaking internally. Plug the line and see what happens. IF nothing then get your codes read and return here for follow up. bookmark the page to make it easy to get back as all you need is the page link and your user name and password.
Thank you so much! I'm worried less about transmission now. WHEW! I will do all that tonight as soon as I get home from work. I appreciate your help.
Transmission is at the bottom of my list.
Went home and checked the vacuum line; no leaks/hissing noise. Went to Auto Zone and they ran the diagnostic for free and it turned out the Idle Air Control Valve went bad. Unplugged it and apparently the car should have stalled or not even started then, but instead it started and instantly revved up to over 4,000 rpms. Replaced the valve and it's back to normal - $29 part. As a bonus, the diag test showed no other engine issues (other than low coolant, which was a super easy fix, of course).
I am glad it was simple, Thanks for letting me know what it was.
Thank you too! Have a great day.