Diesel fuel in oil contamination - what are the reasons to look out for?

[Fbo974]

Yeah Alben is right.

The fuel injector lines go through the rocker cover and into the injectors.

They are prone to leaking and have no rubber seal. They are supposed to be replaced every 5 times they are removed. They are also sensitive to being torqued to within spec. In my case my lines were over-tightened by a mechanic and leaking significant amounts of diesel into the sump.

If they leak there would usually be no visibly external signs, but you would expect the level of oil in the sump to rise as it becomes diluted with diesel. Eventually the level of oil becomes so high and the oil so thin that it can seep past the seals in the turbo and the motor start to run on ithe oil/diesel mix that is in the sump.

Even with smaller amounts you'd also expect the oil to smell like diesel - at least a little bit.

The workshop manual at the following link has some images of the lines to get your heads around it and details of the torque specs for the lines. http://faq.out-club.ru/download/paje...7/index_M1.htm

To get access to the lines you need to remove the EGR and associated intake gear. Basically you need to remove everything on the passenger side of the motor that is above the intake manifold.

To torque the lines up again you need a fairly small torque wrench and some crows foot sockets for the wrench. Mitsubitshi recommend a specialised socket that they sell but it isn't necessary.

Its not the hardest job but takes a bit of time.

thanks for these precision Pajflareo

[Fbo974]

Oil level is the same , nothing change for the moment

[Fbo974]

Did you run the fuel line pressure test with your scanner?

So , pressure line at idle is 320 bars , what do you think about that ?

Oil level began to up again , about 3mm more on dipstick...... due to Covid19 i will never have my fuel return lines , a lot of countries closed there frontiers

[DibbyDibbyDJ]

For idling that is spot on. Some bi directional scan tools can do a fuel leak test to test the pipe connections, and also the return lines internally. This program ramps up the fuel pressure to maximum to allow you to look for leaks externally, and also check for oil dilution if it is an internal leak. Hopefully the scan tool you have access to can do this.



Also in the data section will be an oil dilution figure in cc. This is a calculation of how much fuel it expects to be in the oil as a normal byproduct of DPF regeneration. It is only a calculation though, not exact. this figure should be reset after every service, to allow for an accurate figure to be displayed. If the car is struggling to regenerate this will rise quite quickly and needs to be addressed.

[Fbo974]

Thanks for these presicion i will check oil dilution in data tomorrow or on monday

I don't think my scantool can do a fuel leak test not sure but i'll check it

[DibbyDibbyDJ]

An other way is to do a SMALL INJECTION QUANTITY LEARNING as during this the pressure ramps up to maximum at the end.

[Piet Potjie]

Oil blotter test

This test will give an indication whether the amount of diesel in the oil is increasing or not. Raw diesel fuel that has diluted oil can be clearly seen as a light yellow ring around the outside. Refer to the picture. Just put a drop of oil on some white paper and give it an hour or two. Good check for you guys to do after a regen.

[Fbo974]

An other way is to do a SMALL INJECTION QUANTITY LEARNING as during this the pressure ramps up to maximum at the end.

I will try it this weekend thanks

[Fbo974]

Also in the data section will be an oil dilution figure in cc. This is a calculation of how much fuel it expects to be in the oil as a normal byproduct of DPF regeneration. It is only a calculation though, not exact. this figure should be reset after every service, to allow for an accurate figure to be displayed.

So , oil dilution is 0cc , on the scan tool

[Fbo974]

Hi guyz ,
maybe a stupid question, but does dpf delete affect oil dilution ?
I'm asking this b'cause I discovered that my dpf was deleted, and of course I did not know it before buying the vehicle.
It was by dismantling my cat to clean it before emission control each 2 years that I discovered it 2 weeks ago.

We can see here the result which was very conclusive


and the other side


here the empty dpf ,


do i need to shunt these hoses ?


my oil level has not changed for around 3000kms ,
It's a bit of a headache trying to find out what's going on with this engine

[Fbo974]

The fuels lines that I ordered in February have still not arrived, and the shop don't know when it will be there .
Basically, I thought I had a regeneration problem, and thought it might be because my level was increasing .

when I had removed the surplus of oil from the engine the first time at around 202 thousand and a few, I had driven a little after about 250 / 300kms it seems to me, and the level had increased by a few millimeters , and this level hasn't changed since .

Could I have had a "seized" injector at one time and having put a fuel additive would have solved the problem?

[Seigried]

If the injector is soiled and not broken then an aditive may help. I have liquimolly diesel purge plus which is a bit more involved than just pouring it into the tank.
When you do this replace the fuel filter and add some biocide into the tank incase your issue is caused by sludge.

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