PLATE AS 6Y3926 - Caterpillar

Probable Causes
Misreading oil level
Oil leaks
Engine crankcase breather
Oil level
Air intake and exhaust system
Turbocharger
Low compression (cylinder pressure)Recommended Actions
Misreading Oil Level
Accurately measure the consumption of oil and fuel over a period of 50 engine hours.
If the oil consumption is greater than 0.2% of the fuel consumption, use the following procedure in order to investigate the cause of the high oil consumption. Oil Leaks
Check for evidence of oil leaks on the engine.
Rectify any oil leaks from the engine.
Check for evidence of oil in the coolant.
If no oil leaks are identified, refer to "Engine Crankcase Breather". Engine Crankcase Breather
Check the engine crankcase breather for blockage or restrictions.
Check for excessive oil from the outlet of the breather.
Repair all defects. Verify that the repair has eliminated the fault.
If no faults are found, refer to "Oil Level". Oil Level
Check the oil level in the engine.
If the oil level is high, check for contamination of the oil with coolant. Refer to Troubleshooting, "Coolant in Engine Oil".
If no contamination is identified, remove any excess oil.
If the oil level is satisfactory, refer to "Air Intake and Exhaust System". Air Intake and Exhaust System
Check the air filter restriction indicator, if equipped.
Ensure that the air filter is clean and serviceable.
Check the air intake and the exhaust system for the following defects:
Blockages
Restrictions
Damage to the air intake and exhaust lines and hoses
Make all necessary repairs to the engine.
Ensure that the repairs have eliminated the fault.
If no faults are found, refer to "Turbocharger". Turbocharger
Note: The turbocharger that is installed on this engine is a nonserviceable item. If any mechanical fault exists, then the turbocharger must be replaced.
Check that the oil drain for the turbocharger is not blocked or restricted.
Check the turbocharger for evidence of internal oil leaks.
If necessary, replace the turbocharger. Refer to Disassembly and Assembly, "Turbocharger - Remove" and Disassembly and Assembly, "Turbocharger - Install".
Check that the repairs have eliminated the faults.
If the repairs have not eliminated the fault proceed to "Low Compression (cylinder pressure)". Low Compression (cylinder pressure)
Perform a compression test. Refer to Systems Operation, Testing and Adjusting, "Compression - Test ".
If low compression is noted on any cylinders, investigate the cause and rectify the cause. Possible causes of low compression are shown in the following list:
Loose glow plugs
Faulty piston
Worn piston rings
Worn cylinder bores
Worn valves
Faulty cylinder head gasket
Damaged cylinder head
Perform all necessary repairs.
Ensure that the repairs have eliminated the faults.