M11 Industrial Operation and Maintenance – Fuel Consumption Excessive

Symptom Tree  

Verify the complaint

If low power is relevant, refer to the Engine Power Output Low symptom tree. If acceleration is poor, refer to the Engine Acceleration or Response Poor symptom tree. If fuel consumption is relevant, continue with this tree.


Lubricating oil level is above specification

Check the oil level. Verify the dipstick calibration and oil pan capacity. Fill the system to the specified level. Refer to Procedure 007-043 (Lubricating Oil Level) in Section 3.


Air intake system restriction is above specification

Check the air intake system for restriction. Clean or replace the air filter and inlet piping as necessary. Refer to Procedure 010-024 (Air Leaks, Air Intake and Exhaust Systems) in Section 5.


Fuel leak

Check the fuel lines, fuel connections, and fuel filters for leaks. Check the fuel lines to the supply tanks. Refer to the OEM service manual.


Operator technique is not correct

Refer to Procedure 101-015 (Operating the Engine) in Section 1.


Equipment and environmental factors are affecting fuel consumption

Consider ambient temperatures, wind, tire size, axle alignment, routes, and use of aerodynamic aids when evaluating fuel consumption.


Speedometer is malfunctioning or the road speed is excessive

Calibrate the speedometer. Refer to the OEM service manual.


Hubometer or odometer is miscalibrated

Check the hubometer and odometer calibrations. Calibrate or replace the hubometer or odometer, if necessary. Calculate fuel consumption with new mileage figures.

Contact a Cummins Authorized Repair Facility

Last Modified:  19-Nov-2004