Mechanics

GT1 ALTERNATOR OR STARTER?

2004 Pontiac Grand Prix

2004 Grand Prix GT1, 67,500 miles, 6cyl.

The quick and dirty:

1. Sometimes hard to shift out of park (maybe every 2 out of 5 ocassions). Ocassional light " thump" when shifted into reverse and/or drive.
2. Light clicking sound from under left side of car when accelerating, but stops after a few seconds.
3. Drive non-stop (100+ miles) then park it for a 2-4 hours. Car will start then stall unless tapping the accelerator. If it sits overnight, starts strong with no stalling.
4. Sometimes exterior lights and interior lights/accessories dim when starting, then suddenly go full power (not every time or even every day driven).
5. After filling gas tank, sputters while driving, but then stops. Ride improves as gas level decreases.
6. Ocassionally, engine is louder when running AC. Other times it runs smoothly and quietly.

Not running hot; no indicators for battery, engine or anything else. Could it be the alternator? The starter?

Thanks in advance!
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MarieK
September 21, 2007.



The stalling could be from carbon buildup in the throttle body. The dim lights could be a battery issue. Check the battery for leaks at the positive terminal or excessive corrosion.

Dennyp
Oct 2, 2007.