Ford 7.3L Powerstroke Excessive Crankcase Pressure/White Smoke


Problem: Excessive crankcase pressure or excessive white smoke

Causes: Fuel, air, and moisture forced past the rings into the crankcase.

Solution: Treat with Stiction Eliminator to free up both sides of piston rings. If the piston rings are worn out, they will need to be replaced.


Some blow-by is normal on any diesel engine. This is because the combustion pressure is just too great for the piston rings to hold completely.
Excessive blow-by can be caused by piston rings that are sticking in the bore. One of the ways to check if blow-by is too great is to put your oil filler cap upside down on the filler hole. If the cap gets blown off, there is too much pressure in the crankcase.

Blow-by can be caused by piston rings that are worn out. A cylinder with worn out rings will have low compression and will likely cause a misfire. These piston rings need to be replaced.

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