Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

NO. 21 ENGINE NOISE [AJ] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Is squeal, click or chirp sound present?	Yes	Inspect engine oil level or drive belts.
1	Is squeal, click or chirp sound present?	No	Go to the next step.
2	Is rumble or grind sound present?	Yes	Inspect drive belt.
2	Is rumble or grind sound present?	No	Go to the next step.
3	Is rattle sound present?	Yes	Inspect location of rattle for loose parts.
3	Is rattle sound present?	No	Go to the next step.
4	Is hiss sound present?	Yes	Inspect for the following: Vacuum leakage Spark plug loose Intake-air system leakage VAD control system operation
4	Is hiss sound present?	No	Go to the next step.
5	Is rap or roar sound present?	Yes	Inspect exhaust system for loose parts.
5	Is rap or roar sound present?	No	Go to the next step.
6	Is knock sound present?	Yes	Go to symptom troubleshooting "NO. 13 KNOCKING/PINGING -- ACCELERATION/CRUISE ".
6	Is knock sound present?	No	If noise comes from engine internal, inspect for friction gear, timing chain or HLA noise.
7	Verify test results. If okay, return to diagnostic index to service any additional symptoms. If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, reprogram PCM if later calibration is available. Retest.