Check for leakage at the seals at each end of the crankshaft. Look for leakage at the oil pan gasket and all lubrication system connections. Look for any oil that may be leaking from the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty crankcase breather will cause high pressure in the crankcase. A dirty crankcase breather will cause the gaskets and the seals to leak.
Oil leakage into the combustion area of the cylinders can be the cause of blue smoke. There are four possible ways for oil leakage into the combustion area of the cylinders:
- Oil leakage between worn valve guides and valve stems
- Worn components or damaged components (pistons, piston rings, or dirty oil return holes)
- Incorrect installation of the compression ring and/or the intermediate ring
- Oil leakage past the seal rings in the impeller end of the turbocharger shaft
Excessive oil consumption can also be the result if oil with the wrong viscosity is used. Oil with a thin viscosity can be caused by fuel leakage into the crankcase or by increased engine temperature.