NO.21 ENGINE NOISE [MZR 1.3, MZR 1.5]

id0103d7802700

21

ENGINE NOISE

DESCRIPTION

•  Engine noise from under bonnet.

POSSIBLE CAUSE

Squeal, click or chirp noise:

•  Improper drive belt tension

•  Loose installation of solenoid valves

•  Improper engine oil level

•  Generator installation (alignment)

•  Splash shield or under cover looseness (splashed water to drive belt)

•  Drive belt auto tensioner bearing damaged

Rumble or grind noise:

•  Improper drive belt tension

Rattle sound noise:

•  Loose parts

Hiss sound noise:

•  Air leakage from intake-air system

•  Loose spark plug

•  Vacuum leakage

Rap or roar sound noise:

•  Dynamic damper looseness

•  Exhaust system looseness

•  Intake-air system looseness

•  Variable valve timing actuator malfunction

•  Variable tumble actuator improper operation

Other noise:

•  Tappet noise

•  Timing chain noise

•  PCM malfunction

21	ENGINE NOISE
DESCRIPTION	• Engine noise from under bonnet.
POSSIBLE CAUSE	Squeal, click or chirp noise: • Improper drive belt tension • Loose installation of solenoid valves • Improper engine oil level • Generator installation (alignment) • Splash shield or under cover looseness (splashed water to drive belt) • Drive belt auto tensioner bearing damaged Rumble or grind noise: • Improper drive belt tension Rattle sound noise: • Loose parts Hiss sound noise: • Air leakage from intake-air system • Loose spark plug • Vacuum leakage Rap or roar sound noise: • Dynamic damper looseness • Exhaust system looseness • Intake-air system looseness • Variable valve timing actuator malfunction • Variable tumble actuator improper operation Other noise: • Tappet noise • Timing chain noise • PCM malfunction

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 (alignment) • 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 drive belt. (See DRIVE BELT INSPECTION [MZR 1.3, MZR 1.5].) Replace the drive belt, if necessary. (See DRIVE BELT REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
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		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 chamber • 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 [MZR 1.3, MZR 1.5].)
6		No	If noise comes from engine internal: • Inspect the following: ― 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. (See TIMING CHAIN REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
7	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.3, MZR 1.5].) • If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)