Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
Vehicle » Testing and Inspection » Symptom Related Diagnostic Procedures » Noise, Vibration, and Harshness Diagnosis » Component Tests » Idle Air Control (IAC) Valve  
  Idle Air Control (IAC) Valve  
  1. Open the hood.
  2. Verify the condition by operating the vehicle for a short time.


  • Key symptom is elevated idle speed while noise is occurring.
  • "Snapping" the throttle can induce the noise.
  1. Inspect the ISACV. If physical evidence of contamination exists, install a new ISACV.
  2. While the noise is occurring, either place an EngineEAR probe near the ISACV 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 ISACV is making the noise, install a new ISACV.
  3. Test the vehicle for normal operation.