ABNORMAL NOISE OR KNOCKING
- Check engine oil and coolant level.
- Check engine control system for malfunctioning components. System inspection should include following components: Airflow Meter Vacuum Routing (For Leaks) EGR Valve Position Sensor (If Equipped) Knock Sensor (If Equipped) Throttle Position Sensor Coolant Temperature Sensor Coolant Thermoswitch Inhibitor Switch (A/T) Electronic Controlled Automatic Transmission (ECAT) Unit