Diagnostic Procedure

NO. 21 ENGINE NOISE DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY IF THERE IS SQUEAL, CLICK, OR CHIRP SOUND Is a squealing, click or chirping sound present?	Yes	Inspect the following: Engine oil level Solenoid valves installation Drive belt tension Generator installation Splash shield or under cover loose Auto tensioner bearing damaged Repair or replace the malfunctioning part according to the inspection results.
1		No	Go to the next step.
2	VERIFY IF THERE IS RUMBLE OR GRIND SOUND Is a rumbling or grinding noise present?	Yes	Inspect the following: Drive belt tension (See DRIVE BELT INSPECTION .) Loose parts in engine compartment If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results.
2		No	Go to the next step.
3	VERIFY IF THERE IS RATTLE SOUND Is a rattling noise present?	Yes	Inspect the rattling location for loose parts. Repair or replace the malfunctioning part according to the inspection results.
3		No	Go to the next step.
4	VERIFY IF THERE IS HISS SOUND Is a hissing noise present?	Yes	Inspect the following: Intake air system leakage Spark plug loose Vacuum leakage Repair or replace the malfunctioning part according to the inspection results.
4	VERIFY IF THERE IS HISS SOUND Is a hissing noise present?	No	Go to the next step.
5	VERIFY IF THERE IS RAP OR ROAR SOUND Is a rapping or roar noise present?	Yes	Inspect the following for looseness: Dynamic dumper Exhaust system Intake air system Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	VERIFY IF THERE IS KNOCK SOUND Is a knocking noise present?	Yes	Go to the symptom troubleshooting "NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE". (See NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE .)
6		No	If noise comes from engine internal: Inspect the following: Friction gear Timing chain Tappet noise Valve clearance Variable tumble control system operation Variable valve timing control actuator Repair or replace the malfunctioning part according to the inspection results.
7	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX .) If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.