Cummins ISX11.9 CM2250 – Service Manual Engine Noise Excessive – Connecting Rod

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.

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Fault Code Troubleshooting Manual, Bulletin
4022225, for fault code troubleshooting.

Lubricating oil level is below specification

Check the oil level. Refer to Procedure 007-009 and
Procedure 007-037 in Section 7.

Lubricating oil pressure is below specification

Check the oil pressure. If the pressure is low, refer to
Procedure 007-095 in Section 7.

Internal engine damage

Analyze the oil and inspect the filters to locate an area of probable damage. Refer to
Procedure 007-083 in Section 7
.

Connecting rod capscrews are loose or not tightened correctly

Check the torque on the connecting rod capscrews. Refer to
Procedure 001-014 in Section 1
.

Connecting rod bearings are damaged or worn, are not assembled correctly, or are the wrong bearings

Inspect the connecting rod bearings. Refer to
Procedure 001-005 in Section 1
.