Excursion 4WD V10-6.8L VIN S (2000)
Idle Air Control Valve: Testing and Inspection
IDLE AIR CONTROL (IAC) VALVE NOISE TEST
1. Open the hood.
2. Verify the condition by operating the vehicle for a short time.
NOTE
^
Key symptom is elevated idle speed while noise is occurring.
^
"Snapping" the throttle can induce the noise.
3. Inspect the IAC valve. If physical evidence of contamination exists, install a new IAC valve.
4. While the noise is occurring, either place an EngineEAR probe 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.
5. Test the vehicle for normal operation.
