NO.21 ENGINE NOISE [L8, LF, L5]

id010346802700

21

ENGINE NOISE

DESCRIPTION

Engine noise from under bonnet

POSSIBLE CAUSE

Squeal, click or chirp noise:

•  Improper engine oil level

•  Improper drive belt tension

•  Generator installation

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

Rattle sound noise:

•  Loose parts

Hiss sound noise:

•  Vacuum leakage

•  Loose spark plug

•  Air leakage from intake air system

Rumble or grind noise:

•  Improper drive belt tension

Rap or roar noise:

•  Dynamic dumper looseness

•  Exhaust system looseness

•  Intake air system looseness

Other noise:

•  Tappet noise

•  Timing chain noise

21	ENGINE NOISE
DESCRIPTION	Engine noise from under bonnet
POSSIBLE CAUSE	Squeal, click or chirp noise: • Improper engine oil level • Improper drive belt tension • Generator installation • Splash shield or under cover looseness (splashed water to drive belts) Rattle sound noise: • Loose parts Hiss sound noise: • Vacuum leakage • Loose spark plug • Air leakage from intake air system Rumble or grind noise: • Improper drive belt tension Rap or roar noise: • Dynamic dumper looseness • Exhaust system looseness • Intake air system looseness Other noise: • Tappet noise • Timing chain noise

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Is a squealing, click or chirping sound present?	Yes	Inspect the followings: • Engine oil level • Drive belt tension • Splash shield or under cover looseness • Generator installation
1	Is a squealing, click or chirping sound present?	No	Go to the next step.
2	Is a rumbling or grinding noise present?	Yes	Inspect the followings: • Drive belt tension
2	Is a rumbling or grinding noise present?	No	Go to the next step.
3	Is a rattling noise present?	Yes	Inspect the rattling location for loose parts.
3	Is a rattling noise present?	No	Go to the next step.
4	Is a hissing noise present?	Yes	Inspect the following: • Vacuum leakage • Spark plug looseness • Intake air system leakage
4	Is a hissing noise present?	No	Go to the next step.
5	Is a rapping or roar noise present?	Yes	Inspect for looseness in the following: • Dynamic dumper • Intake air system • Exhaust system
5	Is a rapping or roar noise present?	No	Go to the next step.
6	Is a knocking noise present?	Yes	Go to symptom troubleshooting "No.13 Knocking/pinging". (See NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [L8, LF, L5].)
6	Is a knocking noise present?	No	If the noise comes from inside the engine, inspect the tappet noise.
7	• Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L8, LF, L5].) ― If the malfunction remains, inspect the related Service 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, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF, L5].)