Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

NO.21 ENGINE NOISE DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Is squeal, click or chirp sound present?	Yes	Inspect the engine oil level or drive belts.
1	Is squeal, click or chirp sound present?	No	Go to the next step.
2	Is rumble or grinding noise present?	Yes	Inspect the drive belts.
2	Is rumble or grinding noise present?	No	Go to the next step.
3	Is rattle noise present?	Yes	Inspect the location of rattle for loose parts.
3	Is rattle noise present?	No	Go to the next step.
4	Is hissing noise present?	Yes	Inspect for the following: Vacuum leakage Spark plug looseness Intake-air system leakage Variable fresh air duct (VFAD) control system operation (13B-MSP (High Power)) (See VARIABLE FRESH AIR DUCT (VFAD) CONTROL SYSTEM OPERATION INSPECTION (13B-MSP (HIGH POWER)) .)
4	Is hissing noise present?	No	Go to the next step.
5	Is rap or roar noise present?	Yes	Inspect the exhaust system for loose parts.
5	Is rap or roar noise present?	No	Go to the next step.
6	Is knocking noise present?	Yes	Go to the symptom troubleshooting "No. 13 Knocking/pinging/detonation-Acceleration/cruise". (See NO.13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE .)
6	Is knocking noise present?	No	If the noise comes from engine internally, inspect for oil pump drive gear or chain noise.
7	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.