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 or damaged piston rings, or dirty oil return holes in the piston.
* Worn or damaged and/or intermediate ring not installed correctly.
* Oil leakage past the seal ring in the impeller end of the turbocharger shaft.
* Oil level too high due to error in filling, mis-marked, or incorrect dipstick.
Too much 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 and results in too much oil consumption.