Fan drive belt is loose
Check the belt tension and tighten if necessary. Refer to procedure 008-002
Fan is loose , damaged, or not balanced
Check the fan. Refer to Refer to the OEM service manual.
Fan clutch, hydraulic pump, or refrigerant compressor noise is excessive
Isolate each component and check for noise. Refer to Procedure 009-016, or the OEM service manual.
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 Procedure 010-024.
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.
Lubricating oil level is above or below specification
Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-037.
Lubricating oil is thin or diluted
Check the viscosity of the oi l sample. Refer to Procedure 007-083 if the lubricating oil is contaminated. If the lubricating oil is contaminated , refer to the Lubricating Oil Contaminated symptom Tree.
Lubricating oil pressure is below specification
Check the oil pressure. Refer to Procedure 007-037. If the pressure is low, refer to the Lubricating Oil Pressure Low symptom tree.
Vibration damper is damaged
Inspect the vibration damper. Refer to Procedure 001-052.
Coolant temperature is above specification
Refer to the Coolant Temperature Above Normal-Gradual Overheat symptom tree.
Drivetrain noise is excessive
Disconnect the drivetrain. Check for engine noise. Refer to the OEM service manual.
Engine mounts are worn, damaged, or not correct
Check the engine mounts. Refer to Procedure 016-002 or Procedure 016-003.
Air compressor noise is excessive
Refer to the Air Compressor Noise Excessive symptom tree.
Overhead adjustments are not correct
Measure and adjust the overhead settings. Refer to Procedure 003-004.
Overhead components are damaged
Inspect the rocker levers, rocker shafts, and valves for damage or excessive wear. Refer to Procedure
003-008.
lnjector(s) are malfunctioning
Perform diagnostics to find the damaged injector (s). Replace the injector(s) as necessary. Refer to
Procedure 006-026 or Procedure 014-008.
Torque converter is loose
Check the torque converter. Refer to the OEM service manual.
Flywheel or flexplate capscrews are loose or broken
Check the flywheel or flexplate and the mounting capscrews. Refer to Procedure 016-005 and
Procedure 016-004 respectively.
Gear train backlash is excessive or the gear teeth are damaged
Check the gear backlash and the gear teeth. Refer to Procedure 001-008.
Main bearing or connecting rod bearing noise
Refer to the Engine Noise Excessive – Connecting Rod symptom tree or the Engine Noise Excessive
– Main Bearing symptom tree.
Turbocharger noise
Refer to the Engine Noise Excessive – Turbocharger symptom tree.
Combustion noise excessive
Refer to the Engine Noise Excessive – Combustion Knocks symptom tree.
Piston or piston rings are worn or damaged
Check for air intake system leaks. Check the pistons and piston rings for wear or damage. Refer
to Procedure 010-024 or Procedure 001-047.
Analyze the lubricating oil and oil filters to locatean area of probable damage and cause. Refer to
Procedure 007-048 and Procedure 007-083.