What causes oil blow-by in a diesel engine?
“Blow-by” is a fairly common term across all types of engines—diesel, gas, etc. For diesels, it’s when compressed air and fuel in the cylinder bore is greater than pressure in the oil pan, and gas leaks past piston rings and down into the crankcase.
What can cause high crankcase pressure in a diesel engine?
When you combine a large cylinder bore, high cylinder pressure through turbocharging, many hours of use and marginal maintenance, excessive blowby is the result. The leakage of any combustion gases, air, or pressure into the engine’s crankcase is considered blowby.
How do you fix blow by oil?
The best way to minimize crankcase vapor pressure – blow-by – is to seal the engine as efficiently as possible from cylinder pressure. One way is to minimize ring end gaps by custom setting the end gaps on the top two rings to fit the way the engine will be run.
Is Blow by bad in a diesel engine?
Engine blow-by is the term used to describe loss of cylinder compression as it leaks past the piston rings into the crankcase. Blow-by is a direct cause of diesel smoke, oil consumption, loss of compression, and high levels of soot in the lubricating oil. Blow-by is usually regarded as an indicator of wear.
How do you fix high crankcase pressure?
How much Blowby is normal Cummins?
1/2 quart is fine. Cummins even has a spec saying how much oil consumption before they will do warranty. When temperatures are below zero o rings shrink and allow oil to seep into cylinders and burn off until they warm up and expand.
Why is diesel fuel getting into my engine oil?
Some engines may have a crack in their cylinder head which could cause this same problem. But I do not think it is the case with your Caterpillar engine. Please keep in mind that diesel fuel in the crankcase drastically impacts the oil’s lubricity and creates excessive wear in all parts and the turbo bearing.
What causes excessive blowby in a diesel engine?
Every engine has some level of blowby, but when it comes to large diesels, the concern is amplified. When you combine a large cylinder bore, high cylinder pressure through turbocharging, many hours of use and marginal maintenance, excessive blowby is the result.
How to avoid common causes of blow by and oil consumption?
Here are some common causes of blow-by and excessive oil consumption and how you can avoid them on your next engine build. The combustion process is never perfect. Even the best street engine never seals all that combustion pressure. A certain amount of cylinder pressure will always find its way into the oil pan.
Why is the oil blowing out of my Turbo?
In This List a Lot of the Time The Turbo Can Still Be “Good” But Blowing Oil. The Top Reasons Why a Turbo Blows OIl: The Oil Drain Size Is Too Small. Most Aftermarket Drain Fittings Have too Small of an Inside Diameter Which is Often the Problem.