ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – Engine Noise Excessive — Combustion Knocks

Symptom Tree  t048

This is symptom tree t048
Cause Correction

Refer to Engine Noise Diagnostic Procedures – General Information at the end of Section TS before using this symptom tree.

Electronic fault codes active or high counts of inactive fault codes

Read the fault codes with an electronic service tool. Refer to Section TF in Troubleshooting and Repair Manual, ISB, QSB4.5, QSB5.9, QSB6.7, ISC, QSC8.3, ISL and QSL9 Engines, CM850 Electronic Control System, Bulletin 4021416 or Troubleshooting and Repair Manual, Electronic Control System, ISC, QSC8.3 and ISL Engines, Bulletin 3666271.


Fuel grade is not correct for the application or the fuel quality is poor

Operate the engine from a tank of high-quality fuel. Refer to the Fuel for Cummins Engines, Bulletin 3379001.


Air in the fuel system

Check for air in the fuel system. Vent air from the system. Refer to Procedure 006-003.


Coolant temperature is above specification

Refer to Procedures 008-018, 008-020, or 008-103.


Injector is malfunctioning

Perform the automated cylinder performance test. Replace injectors as necessary. Refer to Procedures 006-026 and 014-008.


Overhead adjustments are not correct

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


Camshaft timing is not correct (after engine rebuild or repair)

Check the gear train timing alignment. Refer to Procedure 001-012.

Last Modified:  20-Jun-2005