#
NO.21 ENGINE NOISE [WITHOUT WU-TWC]

id0103008027c6

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