Cummins ISX11.9 CM2250 – Service Manual Engine Will Not Crank or Cranks Slowly (Air Starter)

Air pressure is low in the air tanks

Increase air pressure with an external air source. Refer to the OEM service manual.

Engine-driven units are engaged

Disengage engine-driven units.

Lubricating oil does not meet specifications for operating conditions

Change the oil and filters. Refer to Procedure 007-037 and
Procedure 007-013 in Section 7. Use the oil type recommended in Section V of the engine operation and maintenance manual.

Starting motor is malfunctioning or starting motor is not correct

Check the starting motor operation. Compare the starting motor with the engine and vehicle specifications. Refer to the OEM service manual.

Starting motor pinion or ring gear is damaged

Remove the starting motor, and inspect the gear. Refer to Procedure 013-020 in Section 13,
Procedure 016-005 in Section 16, and the OEM service manual.

Crankshaft rotation is impaired

Check the crankshaft for ease of rotation. Refer to
Procedure 001-016 in Section 1
.

Hydraulic lock in a cylinder

Remove the injectors and rotate the crankshaft. Look for the source of fluid in the cylinder. Refer to Procedure 006-026 in Section 6 and
Procedure 001-016 in Section 1.

Internal engine damage

Analyze the oil and inspect the filters to locate an area of probable damage. Refer to Procedure 007-083, and
Procedure 007-013 in Section 7. Remove the oil pan and inspect for damaged camshaft, cam followers, push rods, pistons, and liners. Refer to
Procedure 007-025 in Section 7.