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Excessive Crankcase Pressure or Excessive White Smoke When Removing Oil Fill Cap

Problems

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 and Diesel Extreme to free up both sides of piston rings. If the piston rings are worn out, they will need to be replaced.

Details

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.

The contents of HotShotsSecret.com, such as text, graphics, images, and other material contained on the Diagnose Your Diesel section are for informational purposes only. Always seek the advice of your mechanic or other qualified professional with any questions you may have regarding your vehicle’s condition.

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