What causes low idle at stops (e.g. red lights)

2001 OLDSMOBILE ALERO
88,000 MILES
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JPOZ
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  • 1 POST
My 2001 olds alero idles low (approx 300-500)and almost dies at red lights. A pepboys center said the car generates no codes when tested on the pepboys computer. They do not know the reason it passes the diagnostic test, but still idles low. Also, when idling low the serpentine belt chirps, but they said the belt is working properly.

Please help diagnose the problem.

joseph
Sep 27, 2011 at 11:12 PM
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DRCRANKNWRENCH
  • ✓ASE Certified Mechanic
  • 3,380 POSTS
  • ASE Certified Mechanic
The most likely part that is causing the problem is the Idle Air Control Valve, IACV. It controls the idle at low speeds and idle as the engine load increases.
When you replace this part, check for vacuum leaks as well.
Sep 27, 2011 at 11:41 PM
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