Cummins ISX11.9 CM2250 – Service Manual Engine Noise Excessive – Main Bearing

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.

Flywheel is loose or damaged

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

Torque converter is loose

Check the torque converter. Refer to the OEM service manual.

Main bearing capscrews are loose, worn or not tightened correctly

Check the torque on the main bearing capscrews. Inspect the capscrews for wear. Refer to
Procedure 001-006 in Section 1
.

Main bearings are damaged or worn, or the wrong bearings are installed

Inspect the main bearings for damage, excessive wear, and the correct part number. Refer to
Procedure 001-006 in Section 1
.

Thrust bearings are damaged

Inspect the thrust bearing for damage. Refer to
Procedure 001-007 in Section 1
.

Internal engine damage

Analyze the oil and inspect the filters to locate an area of probable damage. Refer to Procedure 007-013 and
Procedure 007-083 in Section 7.