Common Symptoms
- Engine idle speed consistently higher than normal
- Idle speed does not drop to normal when warmed up
- Rough or surging idle condition
- Check Engine Light illuminated
- Engine races on startup or when stopping
Most Likely Root Causes
- Vacuum leak at intake manifold or hoses
- Dirty or sticking idle air control valve
- Throttle body carbon buildup preventing blade closure
- PCV valve or hose leak
- EVAP purge valve stuck open
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Component Location
The idle air control valve is typically mounted on the throttle body or intake manifold near the throttle plate.
Manufacturer Notes
Many vehicles require throttle body cleaning and idle relearn procedures after repairs to restore proper idle control.
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