BOLT 2M5657 - Caterpillar

Probable Causes
Excess engine oil
Oil leaks
High oil temperature
Worn valve guides
Worn valve guide seals
Worn piston rings and worn cylinder walls
Failure of turbocharger oil sealRecommended Repairs
Excess Engine Oil
Ensure that the engine crankcase contains the correct amount of engine oil. If the level of the engine oil increases during engine operation, fuel may be leaking into the oil. Check for fuel in the engine oil. Refer to Troubleshooting, "Fuel In Engine Oil". Ensure that the correct dipstick is installed in the engine.Oil Leaks
Find all oil leaks. Make repairs, as required. Check for dirty crankcase breathers.High Oil Temperature
Check operation of oil cooler and oil temperature regulator. Install new parts, as required. Clean the oil cooler cores.Worn Valve Guides
Inspect the valve guides for wear. Refer to the Specifications module for the maximum permissible wear of the valve guides. If necessary, recondition the cylinder head.Worn Valve Guide Seals
Check for leakage around the seals. If necessary, install new parts.Worn Pistons and/or Worn Cylinder Walls
Piston rings that have excessive wear can cause too much pressure in the crankcase. The additional pressure in the crankcase will cause more than the normal amount of crankcase blowby from the crankcase breather. Use the 8T-2700 Blowby/Air Flow Indicator to check the amount of crankcase blowby. The test procedure is in Special Instruction, SEHS8712. Inspect piston rings and install new parts, as required.Failure of the Turbocharger Oil Seal
If the oil seal in the turbocharger fails, oil will leak into the inlet manifold. Check the inlet manifold for oil. If oil is present, repair the turbocharger.