SEAL-O-RING 7S8561 - Caterpillar

Probable Causes
Oil leaks
Oil consumption
Oil viscosity
Turbocharger sealsRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 1
Troubleshooting Test Steps Values Results
1. Check for Oil Leaks
A. Determine if there is an external oil leak.
1. Look for leakage at the seals at each end of the crankshaft.
2. Look for leakage at the gasket for the engine oil pan and all lubrication system connections.
3. Look for leakage from the crankcase breathers.
High crankcase pressure can cause these conditions.
Leak
Result: Oil is not leaking from the engine.
Proceed to the next step.
Result: Oil is leaking from the engine.
Repair the cause of the leak.
If the problem is not resolved, proceed to Test Step 3.
2. Check for Oil Consumption
A. Determine if there is a leak path to the combustion area.
1. Determine if any of the following conditions exist:
- Leaks between worn valve guides and valve stems
- Plugged return holes for the engine oil.
- Worn or damaged pistons or piston rings.
- Incorrect installation of the compression ring and/or the intermediate ring
- Leaks past the seal rings in the turbocharger shaft
- Overfilling of the crankcase
- Wrong oil level gauge or guide tube
- Sustained operation at light loads
Engine oil that is leaking into the combustion area of the cylinders can be the cause of blue smoke.
Ensure that the dipstick is properly calibrated and/or that the dipstick is correct for the application. Calibrate the dipstick and/or replace the dipstick.
Oil
consumption
Result: Oil is not leaking into the combustion area.
Proceed to the Test Step 3.
Result: Oil is leaking into the combustion area.
Repair the cause of the excessive oil consumption.
If the problem is not resolved, proceed to the next step.
3. Check the Oil Viscosity
A. Make sure that the engine is supplied with the correct engine oil.
B. For the correct engine oil to use, refer to the Operation and Maintenance Manual.
Low oil viscosity can be caused by fuel leakage into the crankcase or by increased engine temperature.
Viscosity
Result: The engine oil is of the correct type.
Proceed to Test Step 4.
Result: The engine oil is not of the correct type.
Determine the reason why incorrect oil is in the engine.
Change the engine oil and the engine oil filter
If the problem is not resolved, proceed to the next step.
4. Check the Turbocharge Shaft Seals
A. Determine if the shaft seals for the turbocharger are leaking.
1. Remove the air inlet piping and the exhaust outlet piping from the turbocharger.
2. Check the compressor wheel and the turbine for evidence of an oil leak.
Refer to Systems Operation/Testing and Adjusting, "Turbocharger Inspect".
Leak
Result: The turbocharger is NOT OK.
Repair the turbocharger or replace the turbocharger.