Operation and maintenance manual

Troubleshooting Symptoms Charts QSB4.5 and QSB6.7
Page TS-24 Section TS - Troubleshooting Symptoms
Engine Noise Excessive
Cause Correction
STEP 1
Fan drive belt is loose, tight, or not in alignment
............. Check the fan drive belt. Refer to Section 3 .
OK
Go To Next Step
STEP 2
Lubricating oil is thin or diluted
.............
Refer to the Lubricating Oil Specifications in
Section V. If the oil pressure is low, refer to the
Lubricating Oil Pressure Low troubleshooting
symptom tree in Section TS.
OK
Go To Next Step
STEP 3
Vibration damper is damaged or loose
.............
Inspect the vibration damper. Contact a
Cummins® Authorized Repair Location.
OK
Go To Next Step
STEP 4
Air intake or exhaust leaks
.............
Check for loose or damaged piping connections
and missing pipe plugs. Check the turbocharger
and exhaust manifold mounting. Refer to Section
3 .
OK
Go To Next Step
STEP 5
Air intake or exhaust piping is contacting the
chassis or cab
.............
Inspect the air piping, chassis, and cab for contact
points. Refer to the OEM service manual.
OK
Go To Next Step
STEP 6
Air intake system restriction is above specification
.............
Check the air intake system for restrictions. Clean
or replace the air filter and inlet piping as
necessary. Refer to Section 4 .
OK
Go To Next Step
STEP 7
Coolant temperature is above specification
.............
Refer to the Coolant Temperature is Above Normal
- Sudden Overheator the Coolant Temperature is
Above Normal - Gradual Overheat symptom tree.
OK
Go To Next Step
STEP 8
Engine mounts are worn, damaged, or not correct
.............
Check the engine mounts. Refer to the OEM
service manual.
OK
Go To Next Step
STEP 9
Fan clutch, hydraulic pump, or refrigerant
compressor noise is excessive
.............
Isolate each component and check for noise. Refer
to the OEM service manual.
OK
Go To Next Step