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NO.21 ENGINE NOISE [L3]

BME010300000W23

21 | ENGINE NOISE
--- | ---
DESCRIPTION | Engine noise from under hood
POSSIBLE CAUSE | Squeal, click or chirp noise: • Improper engine oil level • Improper drive belt tension 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 sound noise:

• Exhaust system looseness

Other noise:

• Camshaft friction gear noise or MLA noise
• Timing chain noise

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
--- | --- | --- | ---
1 | Is squeal, click or chirp sound present? | Yes | Inspect engine oil level or drive belts.
No | Go to next step.
2 | Is rumble or grind sound present? | Yes | Inspect drive belts.
No | Go to next step.
3 | Is rattle sound present? | Yes | Inspect location of rattle for loose parts.
No | Go to next step.
4 | Is hiss sound present? | Yes | Inspect for following: • Vacuum leakage • Spark plug looseness • Intake-air system leakage
No | Go to next step.
5 | Is rap or roar sound present? | Yes | Inspect exhaust system for loose parts.
No | Go to next step.
6 | Is knock sound present? | Yes | Go to symptom troubleshooting "No.11 Knocking/pinging".
No | If noise comes from engine internal, inspect for friction gear, timing chain or MLA noise.
7 | Verify test results. • If okay, return to diagnostic index to service any additional symptoms. • If malfunction remains, replace PCM.