Why/How Does Fuel Get Into The Oil?

[fairhaven]

I'm no mechanic so I am trying to understand how this happens. Is it possible that this happens because of not completing the regen when it starts? I now have about 13,000 miles on my truck and my oil level has not gone up at all between oil changes, however when I see then "Cleaning Exhaust Filter" I drive around (I live in the county where the normal speeds are 40mph) until the regen is complete which most times is about 20 minutes total. What is the tell tale sign that there is fuel in the oil? Thanks

[Shinny]

Fuel is sent into the motor during the regen process. It's sent thru the exhaust stroke to get to the dpf. Once in the dpf, it's used to burn the soot for better emissions

[elibenson]

On the exhaust stroke they inject more fuel to get some fuel into the exhaust stream. Not all that fuel ends up in the exhaust. Some of it slips past the rings into the oil.

Fuel in the oil = bad news. That is why the majority of the people on here do a DPF delete and tune their trucks to stop the regen process.

Oil being over full is usually a good sign that you have fuel in your oil. To be absolutely sure, you can send a sample of your oil to Blackstone Labs and have it analyzed. They will tell you if there is any apparent engine wear, any coolant in the oil, etc. As well as the fuel dilution percentage. There are other companies that do this too, but Blackstone is the one that most people on here use.

[Cougarpuller08]

Rather than spending some time typing, here a link. It shows you exactly how the 4 strokes of the motor work.


HowStuffWorks "Diesel Engines vs. Gasoline Engines"

Whenever you introduce fuel, whether it is gasoline or diesel, during a non combustion stroke, you will in effect wash the cylinder walls of any oil left over for lubrication. This causes the rings to scrape more material from the cylinder due to not having a small buffer of oil between the two.

[benjamin24]

Now my friend, you are starting to see the big picture hopefully.

It's always been my theory that the people who see the most oil are those who do alot of city driving. ie. stop and go traffic, not being able to keep up the necessary speed to complete the regen, or just shutting the truck off when you reach your destination. I can't tell you how many times it's started regen on me a minute before I reach my offramp where I would have to come to a complete stop effectively killing the regen. I don't know exactly how the regen operates, but believe the fuel that is going to be used to burn the soot is ultimately dumped into the engine. (I mean where else is it gonna go? they couldn't possibly leave raw fuel in your exhaust could they?) I saw oil gains on my new 09 before its first oil change. The dealer I took it to for its first service at 5k miles the tech comes out and tells me my oil looks in his words "nasty". And explains to me the fuel in the oil (which I knew thanks to this forum, but not from my salesman) and how bad it is for the engine and what a bad design it was. And that half of the trucks that came in were dpf problems the other half were radiators. I made my mind up that day to tune my truck.

[j21black]

Originally Posted by benjamin24

Now my friend, you are starting to see the big picture hopefully.

It's always been my theory that the people who see the most oil are those who do alot of city driving. ie. stop and go traffic, not being able to keep up the necessary speed to complete the regen, or just shutting the truck off when you reach your destination. I can't tell you how many times it's started regen on me a minute before I reach my offramp where I would have to come to a complete stop effectively killing the regen. I don't know exactly how the regen operates, but believe the fuel that is going to be used to burn the soot is ultimately dumped into the engine. (I mean where else is it gonna go? they couldn't possibly leave raw fuel in your exhaust could they?) I saw oil gains on my new 09 before its first oil change. The dealer I took it to for its first service at 5k miles the tech comes out and tells me my oil looks in his words "nasty". And explains to me the fuel in the oil (which I knew thanks to this forum, but not from my salesman) and how bad it is for the engine and what a bad design it was. And that half of the trucks that came in were dpf problems the other half were radiators. I made my mind up that day to tune my truck.

Happened to me today - I am thinking a tune is going to be a must vs. just something I want...

[benjamin24]

If you're gonna keep the truck a while then I would look into it personally. It quite possibly could void your warranty though if caught. Its one of those things that you have to decide whats more important to you.

[promodracer]

Originally Posted by benjamin24

If you're gonna keep the truck a while then I would look into it personally. It quite possibly could void your warranty though if caught. Its one of those things that you have to decide whats more important to you.

Don't forget some hpfp leak fuel by the seals if lift pump pressure is over 15lbs.
Say evidence of this on my 2010 hpfp when at floor it diesel.