What are all the possible scenarios as to how diesel could..

[ToMeToYou]

What are all the possible scenarios as to how diesel could get into the engine oil?

I know..

1. Is leaky injectors.

Specifically im talking about a DPF fitted A17DTJ engine found in vauxhall cars. Someone told me a DPF that fails to regenerate could dump the diesel into the engine oil? How true is that? what are ALL possible scenarios?

[bobtail4x4]

cracked head?

[Desiderata]

Some manufacturers forced dpf regens work by injecting extra fuel to make the system run hotter to burn away excess soot. If these regens are interupted and not allowed to complete, the small amount of excess fuel ends up in the sump.
Not a big problem if it only happens once or twice, but if repeated over a longer period, can eventually dilute the oil with diesel to dangerous levels.
Mazdas were bad for this, not sure which other makes.

[Truckosaurus]

Dodgy EGR valves will dump all sort of nasty stuff where it is no supposed to be.

OP: How much fuel is in the oil? Even my sister's shoddy old Fiesta has a 'oil quality' warning light that comes on when there's a certain level of fuel in the oil - it normally comes on before it's annual service in an apparently healthy engine.

[Jazoli]

Vauxhalls do exactly as stated above, I noticed the oil level rising on my Insignia and its because there is no indication of a regen occurring and I was doing relatively short journeys.

[tin duck dave]

Desiderata said:

Some manufacturers forced dpf regens work by injecting extra fuel to make the system run hotter to burn away excess soot. If these regens are interupted and not allowed to complete, the small amount of excess fuel ends up in the sump.
Not a big problem if it only happens once or twice, but if repeated over a longer period, can eventually dilute the oil with diesel to dangerous levels.
Mazdas were bad for this, not sure which other makes.

Mercedes sprinter was very prone to this , even had a couple have engines pick up on oil due to high sump level while running rental fleet. Used to come up with HI warning on dash and would get customers commenting on it saying hello when they started.