Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

NO. 21 ENGINE NOISE (SKYACTIV-G 2.0, SKYACTIV-G 2.5) - DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY IF THERE IS SQUEAL, CLICK, OR CHIRP SOUND Is squeal, click or chirp sound present?	Yes	Inspect the following: Engine oil level Solenoid valves installation Drive belt tension Generator installation Auto tensioner bearing damaged Splash shield or under cover loose 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 rumble or grinding sound present?	Yes	Inspect the following: Drive belt tension 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 rattle sound present?	Yes	Inspect the location of rattle for loose parts. Repair or replace the malfunctioning part according to the inspection results.
3	VERIFY IF THERE IS RATTLE SOUND Is rattle sound present?	No	Go to the next step.
4	VERIFY IF THERE IS HISS SOUND Is hiss sound present?	Yes	Inspect the following: Vacuum leakage Spark plug loose Intake-air system leakage Repair or replace the malfunctioning part according to the inspection results.
4	VERIFY IF THERE IS HISS SOUND Is hiss sound present?	No	Go to the next step.
5	VERIFY IF THERE IS RAP OR ROAR SOUND Is rap or roar sound present?	Yes	Inspect the following: Exhaust system installation Intake-air system installation Dynamic damper installation 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 knocking noise present?	Yes	Perform the symptom troubleshooting "NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE". (See NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE .)
6	VERIFY IF THERE IS KNOCK SOUND Is knocking noise present?	No	If noise comes from engine internal: Inspect the following: Timing chain Hydraulic lash adjuster (HLA) noise Electric variable valve timing actuator Hydraulic variable valve timing actuator Engine compression Repair or replace the malfunctioning part according to the inspection results.
7	Verify the 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.