NO.21 ENGINE NOISE

BHE010300103W23

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 variable fresh air duct (VFAD) control system operation (13B-MSP (High Power))
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.
No
Go to the next step.
2
Is rumble or grinding noise present?
Yes
Inspect the drive belts.
No
Go to the next step.
3
Is rattle noise present?
Yes
Inspect the location of rattle for loose parts.
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))
No
Go to the next step.
5
Is rap or roar noise present?
Yes
Inspect the exhaust system for loose parts.
No
Go to the next step.
6
Is knocking noise present?
Yes
Go to the symptom troubleshooting "No.13 Knocking/pinging/detonation-Acceleration/cruise".
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 Information and perform the repair or diagnosis.