PontiacBonnevilleClub.com

I have an '04 Bonneville SE that is doing the following:

1. Starts fine and runs fine when cold/getting to hot.
2. Normally runs fine when hot.
3. Randomly hesitates, then surges and seems to downshift when in 2nd or 3rd gear. This lasts for about 3-4 (nervous!) seconds and then goes back to normal. It can occur again within a minute, or it can go without doing that again for another 45 minutes.

I've replaced the idle air control valve and cleaned the maf. Still happening.

Any ideas? I'm very grateful to all of you for your help. I've learned a lot on this site.

Barry

I would check the ignition system over as well as the crank position sensor.

Thank you, sir.

Can you tell me what you'd test first? I'm a newbie to auto repair and also would appreciate your guidance if I'm crossing into the zone of a boy trying to do a man's work.

Carl...I'm writing to thank you. I replaced the coils last night and the problem seems to have gone away. I appreciate your efforts.

Barry