N14 Base Engine Troubleshooting and Repair Manual – 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.

Engine is operating at low ambient temperature

Check the shutters and engine compartment air. Refer to the Operation of Diesel Engines in Cold Climates, Bulletin 3379009.

 

Ether starting aid is malfunctioning

Repair or replace the ether starting aids. Refer to the manufacturer’s instructions.

 

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 Fuels for Cummins Engines, Bulletin 3379001.

 

Air in the fuel system

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

 

Coolant temperature is below specification

Refer to the Coolant Temperature Below Normal symptom tree.

 

Static injection timing is not correct

Check the static injection timing. Refer to Procedure 006-025.

 

Injector is malfunctioning

Perform the single-cylinder cutout test. Replace the injectors as necessary. Refer to Procedures 006-005 and 006-026.

 

Overhead adjustments are not correct

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

 
Last Modified:  30-Jan-2004