ISM, ISMe, and QSM11 – Engine Noise Excessive — Piston

Symptom Tree  t051

This is symptom tree t051
Cause Correction

Refer to Engine Noise Diagnostic Procedures — General Information at the end of this section before using this symptom tree.

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 Recommendations , Bulletin 3379001.


Overhead adjustments are not correct

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


Injector is malfunctioning

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


Piston pin or bushing is loose, worn, or not installed correctly

Remove the pistons and inspect the piston pin and bushing for damage, wear, and correct installation. Refer to Procedure 001-043.


Cylinder liner, pistons, or piston rings are worn or damaged

Check the pistons, piston rings, and cylinder liner. Refer to Procedures 001-043, 001-047, and 001-028.


Connecting rod is bent or out of alignment

Remove and inspect the connecting rods. Refer to Procedure 001-014.

Last Modified:  13-Oct-2005