Idle Air Control (IAC) Valve
NOTE:
Key symptom is elevated idle speed while noise is occurring.
NOTE:
"Snapping" the throttle can induce the noise.
- Open the hood.
- Verify the condition by operating the vehicle for a short time.
- Inspect the IAC. If physical evidence of contamination exists, install a new IAC.
- While the noise is occurring, either place an EngineEAR near the IAC valve and the inlet tube, or create a 6.35 mm (0.25 in)-12.7 mm (0.50 in) air gap between the inlet tube and the clean air tube. If the IAC valve is making the noise, install a new IAC valve.
- Test the vehicle for normal operation.