ISM, ISMe, and QSM11 – Engine Will Not Crank or Cranks Slowly (Air Starter)

Symptom Tree  t077

This is symptom tree t077
Cause Correction

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 temperature is below specificationthe OEM service manual

Install an oil pan heater, or drain the oil and fill the system with warm oil.


Lubricating oil does not meet specifications for operating conditions

Change the oil and filters. Refer to Procedure
007-013 in Section 7 or
007-025 in Section 7. Use the oil type recommended in Section V of the engine operation and maintenance manual.


Crankshaft rotation is impaired

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


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 manufacturer’s instructions.


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. Referenece the OEM service manual.


Hydraulic lock in a cylinder

Remove the injectors and rotate the crankshaft. Look for the source of fluid in the cylinder. Refer to Procedures
006-026 in Section 6. and
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
007-002 in Section 7.

Last Modified:  24-Sep-2009