2018 Duramax fuel filter in use for 14,000 miles

[wwillson]

The filters always come out with this black coating. The new filter has white filter media. I wonder of the gasoline we put in our cars is as dirty as diesel fuel?

 

[Rat407]

The main issue here in the states is fuel quality. It stinks for the most part. Big oil can do way better but then it would cut into their profits. Sad.

 

[jhellwig]

Refining isn’t a pure process and then their is the mill scale and dirt from the millions on miles of carbon pipe and tanks that is it pumped through. If you could take all the dirt out of that filter and put it in a pile it wouldn’t be as much as you think for the amount fuel you ran.

Gasoline is somewhat cleaner because of the refining process but also doesn’t require as fine of filtering as Diesel engines do.

Bio diesel tends to be a bit dirtier also. Bacterial growth is also an issue that makes a huge black mess.

 

[The motor guy]

Do you notice a lot of sediment in your filter housing?

 

[wwillson]

Do you notice a lot of sediment in your filter housing?

No, there is zero sediment.

 

[The motor guy]

Interesting. I can see dirt sitting on top of my filter when I remove mine.

 

[Chris142]

Mine don't look anything like that

 

[JHZR2]

No, there is zero sediment.

I was very surprised to see sand and metal in the prefilter in my Cummins when I did it today. The prefilter in my MB cars gets dirty, but never the metal and sandy grit I saw in this one. No idea how many miles were on it. It was pretty grimy on the outside...

 

[wwillson]

The prefilter in my MB cars gets dirty, but never the metal and sandy grit I saw in this one.

That's not good. The metal could be getting into the fuel tank from the bleed return from the main pump. Maybe someone here will know more about the fuel system on your year of Cummins.

 

[JHZR2]

That's not good. The metal could be getting into the fuel tank from the bleed return from the main pump. Maybe someone here will know more about the fuel system on your year of Cummins.

Apparently some metal shavings are common on these. Belief is it’s the mechanical lift pump.

 

[wwillson]

Belief is it’s the mechanical lift pump.

That's certainly a lot better than the main pump.

 

[JHZR2]

That's certainly a lot better than the main pump.

Agreed. I’ve also heard it is due to the vibration of the fuel level sender...

 

[AP9]

Agreed. I’ve also heard it is due to the vibration of the fuel level sender...

2017 and newer 6.6L Duramax (L5P and L5D) switched to electric lift pump in the fuel tank, upstream of the fuel filter, very similar to the gasoline-powered trucks. And yes, it is quite possible the whole delivery module unit is vibrating on the bottom of the tank.