C7.1 Engines For Caterpillar Built Machines Caterpillar

Probable Causes

• Misreading oil level

• Oil leaks

• Engine crankcase breather

• Oil level

• Air intake and exhaust system

• Turbochargers

• Low compression (cylinder pressure)

Recommended Actions

Misreading Oil Level

1. Accurately measure the consumption of oil and fuel over a period of 50 engine hours.

2. If the oil consumption is greater than 0.08% of the fuel consumption, use the following procedure to investigate the cause.

Oil Leaks

1. Check for evidence of oil leaks on the engine.

2. Rectify any oil leaks from the engine.

3. Check for evidence of oil in the coolant. If oil is found in the coolant, refer to Troubleshooting, "Coolant Contains Oil".

4. If no oil leaks are identified, refer to "Engine Crankcase Breather".

Engine Crankcase Breather

1. Check the engine crankcase breather for blockage or restrictions.

2. Check for excessive oil from the outlet of the breather.

3. If necessary, replace the filter in the breather.

4. Repair all defects. Verify that the repair has eliminated the fault.

5. If no faults are found, refer to "Oil Level".

Oil Level

1. Check the oil level in the engine.

2. If no contamination is identified, remove any excess oil.

3. If the oil level is satisfactory, refer to "Air Intake and Exhaust System".

Air Intake and Exhaust System

1. Ensure that the air filter is clean and serviceable.

2. Check the air intake and the exhaust system for the following defects:
   • Blockages

   • Restrictions

   • Damage to the air intake and exhaust lines and hoses

3. Make all necessary repairs to the engine.

4. Ensure that the repairs have eliminated the fault.

5. If no faults are found, refer to "Turbochargers".

Turbochargers

Note: The turbochargers that are installed on this engine are nonserviceable items. If any mechanical fault exists, then the faulty turbocharger must be replaced.

1. Check that the oil drains for the turbochargers are not blocked or restricted.

2. Check the turbochargers for evidence of internal oil leaks. If evidence is found of an oil leak into the exhaust system, inspect the diesel particulate filter for blockage of the filter inlet.

3. If necessary, replace the faulty turbocharger. Refer to Disassembly and Assembly, "Turbocharger - Remove" and Disassembly and Assembly, "Turbocharger - Install".

4. Check that the repairs have eliminated the faults.

5. If the repairs have not eliminated the fault, proceed to "Low Compression (cylinder pressure)".

Low Compression (cylinder pressure)

1. Perform a compression test. Refer to Systems Operation, Testing, and Adjusting, "Compression - Test ".

2. 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

3. Perform all necessary repairs.

4. Ensure that the repairs have eliminated the faults.

5. If the fault is not eliminated, contact the technical communicator at a Cat dealer.