Why Does Diesel Enter the Engine Oil in Diesel Engines?
2 Answers
Diesel entering the engine oil in diesel engines is caused by: 1. Damage to the plunger sleeve sealing ring of the fuel injection pump; 2. Excessive clearance between the piston rings and cylinder walls or low cylinder pressure; 3. Failure of oil seals or malfunction of the fuel injector. Methods to address diesel in engine oil: It is necessary to promptly replace the engine oil to avoid affecting engine performance and causing damage to the vehicle. Engine oil, also known as engine lubricant, serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide cushioning and shock absorption for the engine. Diesel is a type of light petroleum product, a complex mixture of hydrocarbons, typically used as fuel for diesel engines.
I've been driving diesel cars for over a decade and once encountered the issue of diesel mixing into the engine oil. That time it was because the injector sealing ring had aged, allowing diesel to leak into the combustion chamber and then enter the crankcase through the piston rings. Diesel diluting the engine oil reduces lubrication effectiveness, and over time the engine becomes prone to overheating or wear. It cost me over 1,000 yuan to fix before realizing it was a sealing issue. I recommend fellow car owners to regularly check injector seals. If you notice the oil smelling like fuel or the oil level rising, get it repaired immediately—don't wait until the engine needs major overhaul. Another possible cause could be internal leakage in the high-pressure fuel pump, which is common in older vehicles. Replacing the pump or O-rings can solve this. Remember to sniff for unusual odors when changing engine oil—it can save you a lot of trouble.
