Centinel System – Repair Manual – Engine Noise Excessive

Interview the operator to verify the complaint

Refer to Driveability-General Information, the Driveability/Low-Power Customer Complaint Form, and the Driveability Checklist at the end of Section TS. Follow the instructions on the forms before continuing with this tree.

Air intake or exhaust leaks

Inspect the air intake and exhaust systems for air leaks. Refer to Procedure 010-024 in Section 10.

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual, CM870 Electronic Control System, Signature™ and ISX Engines, Bulletin
4021334,or the Troubleshooting and Repair Manual, Electronic Control System, Signature™, ISX and QSX15 Engines, Bulletin
3666259,or Troubleshooting and Repair Manual, Power Generation Control Systems, QSX15, QSK23, QSK45, QSK60, QSK78 and QST30 Series Engines, Bulletin
4021419 for fault code troubleshooting.

Lubricating oil level is below specification

Check the oil level. Verify the dipstick calibration and the oil pan capacity. Fill the system to the specified level. Refer to Procedures 007-009
and 007-037 in Section 7.

Fan clutch, hydraulic pump, or refrigerant compressor noise is excessive

Isolate each component and check for noise. Refer to the OEM service manual.

Fan is loose, damaged, or not balanced

Check the fan. Refer to Procedure 008-040 in Section 8.

Air intake or exhaust piping is contacting the chassis or cab

Inspect the air piping, chassis, and cab for contact points. Refer to Procedure 010-031 in Section 10
or Procedure 010-080 in Section 10.

Engine mounts are worn, damaged, loose, or not correct

Verify the condition of the mounts. Refer to Procedure 016-010 in Section 16. Refer to the OEM service manual.

Turbocharger noise

Refer to the Engine Noise Excessive – Turbocharger symptom tree.

Vibration damper has failed

Remove the vibration damper and operate the engine at the rpm where the noise normally occurs. If the noise is still present, proceed to the next step. If the noise is eliminated, replace the vibration damper. Refer to Procedure 001-052 in Section 1.

Drivetrain noise is excessive

Disconnect the drivetrain. Check for engine noise. Refer to the OEM service manual.

Air compressor noise is excessive

Refer to the Air Compressor Noise Is Excessive symptom tree.

Overhead adjustments are not correct

Measure and adjust the overhead settings. Refer to Procedure 003-004 in Section 3.

Overhead components are damaged

Inspect the rocker levers, rocker shafts, and valves for damage or excessive wear. Refer to Procedure 003-009 in Section 3.

Injector is malfunctioning

Perform the single-cylinder cutout test. Replace the injectors as necessary. Refer to Procedure 006-026 in Section 6.

Flywheel is loose or damaged

Check the flywheel. Refer to Procedure 016-005 in Section 16.

Gear train backlash is excessive or the gear teeth are damaged

Check the gear backlash and the gear teeth for excessive wear.
Refer to Procedure 001-088 in Section 1 and
Procedure 007-031 in Section 7.

Main bearing or connecting rod bearing noise

Refer to the Engine Noise Excessive – Main Bearing or Engine Noise Excessive – Connecting Rod symptom trees.

Piston, piston rings, or cylinder liner is worn or damaged

Refer to the Engine Noise Excessive – Piston symptom tree.

Rear engine power take-off (REPTO) noise is excessive

Disassemble and repair the REPTO as necessary. Refer to
Procedure 016-007 in Section 16.

Combustion knocks

Refer to the Engine Noise Excessive – Combustion Knocks symptom tree.

Internal engine damage

Analyze the oil and inspect the filters to locate an area of probable damage. Refer to Procedure 007-013 in Section 7.