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Use the table below to help you find the cause of the symptom. Locate the area where noise occurs. 2. Confirm the type of noise. 3. Specify the operating condition of the engine. 4. Check the specified noise source. If necessary, repair or replace these parts. NVH Troubleshooting — Engine Noise NLEM0116S01 Location of noise Type of noise Operating condition of engine Source of noise Check item Reference page Before warm- up After warm- up When start- ing When idling When racing While driving Top of Ticking or C A — A B — Rocker Hydraulic lash adjuster Rattle C A — A B C Camshaft Camshaft journal clear- Crankshaft Slap or — A — B B — Piston pin Piston and piston pin Slap or A — — B B A Piston slap Piston-to-bore clearance Knock A B C B B B Connecting Connecting rod bushing Knock A B — A B C Main bear- Main bearing oil clear- Front of Tapping A A — B B B Timing Timing chain cracks and Front of Squeak or A B — B — C Other drive Drive belts deflection EM-86, Creaking A B A B A B Other drive Idler pulley bearing Squall A B — B A B Water Water pump operation LC-34, A: Closely related B: Related C: Sometimes related —: Not related NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING SR Commercial Service Tools (Cont’d) EM-81 |