NO.21 ENGINE NOISE [13B-MSP]

id0103f2802700

21

ENGINE NOISE

DESCRIPTION

Engine noise from under the hood.

POSSIBLE CAUSE

Squeal, click or chirp noise:

•  Improper engine oil level

•  Improper drive belt tension

Rattle sound noise:

•  Loose parts

Hissing noise:

•  Vacuum leakage

•  Loose spark plug

•  Air leakage from intake‐air system

•  Improper VFAD control system operation (with VFAD)

Rumble or grind noise:

•  Improper drive belt tension

Rap or roar noise:

•  Exhaust system looseness

Other noise:

•  Oil pump drive gear noise

•  Oil pump drive chain noise

21	ENGINE NOISE
DESCRIPTION	Engine noise from under the hood.
POSSIBLE CAUSE	Squeal, click or chirp noise: • Improper engine oil level • Improper drive belt tension Rattle sound noise: • Loose parts Hissing noise: • Vacuum leakage • Loose spark plug • Air leakage from intake‐air system • Improper VFAD control system operation (with VFAD) Rumble or grind noise: • Improper drive belt tension Rap or roar noise: • Exhaust system looseness Other noise: • Oil pump drive gear noise • Oil pump drive chain 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 • VFAD control system operation (with VFAD) (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP].)
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 [13B-MSP].)
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.