Fuel in oil pan

[PEO]

Pulled my L3650 in after doing some grading and noticed new oil drips. Started checking and found the oil was way over full. Drained at least a quart of oil out to bring it down to the full mark.

I know this can be serious fast... trying to get guidance on where to start... are their seals in the injector pump that fail or possibly an injector.

There is no noticeable heavy exhaust which seems to rule out an injector issue.....

 

[PoTreeBoy]

Pulled my L3650 in after doing some grading and noticed new oil drips. Started checking and found the oil was way over full. Drained at least a quart of oil out to bring it down to the full mark.

I know this can be serious fast... trying to get guidance on where to start... are their seals in the injector pump that fail or possibly an injector.

There is no noticeable heavy exhaust which seems to rule out an injector issue.....

If you're sure it's fuel and not hydraulic fluid, the lift pump is the most likely suspect. Yours has a replaceable diaphragm.

 

[North Idaho Wolfman]

Like @PoTreeBoy said suspect Hydraulic fluid more than diesel.
When the main seal on the hydraulic pump goes bad it pumps oil into the crankcase.
Raw fuel won't get into the crankcase via the injectors, nearly impossible.
You could have a injection pump leak but that too is very unlikely, they normally leak out the top, outside the crankcase, not into it.
The lift pump can go bad and it will allow fuel into the crankcase.
really simple to check that, pull the lift pump leaving it connected to the lines, put a bucket under it and let it sit for a day or two, if there is any fuel in the bucket then there is your culprit.

 

[jwitty]

Like @PoTreeBoy said suspect Hydraulic fluid more than diesel.
When the main seal on the hydraulic pump goes bad it pumps oil into the crankcase.
Raw fuel won't get into the crankcase via the injectors, nearly impossible.
You could have a injection pump leak but that too is very unlikely, they normally leak out the top, outside the crankcase, not into it.
The lift pump can go bad and it will allow fuel into the crankcase.
really simple to check that, pull the lift pump leaving it connected to the lines, put a bucket under it and let it sit for a day or two, if there is any fuel in the bucket then there is your culprit.

You absolutely can get diesel into the crankcase from a leaking injector. Definitely nowhere near "nearly impossible"

 

[North Idaho Wolfman]

You absolutely can get diesel into the crankcase from a leaking injector. Definitely nowhere near "nearly impossible"

HOW?
When it's not running there is no pressure, and there is no way for it to free flow fuel.

I should have added: If it's running on all cylinders, because yes if a cylinder is not firing then it would just inject / leak fuel into the cylinder that is not being used which could end up in the crankcase.

 

[jwitty]

HOW?
When it's not running there is no pressure, and there is no way for it to free flow fuel.

I should have added: If it's running on all cylinders, because yes if a cylinder is not firing then it would just inject / leak fuel into the cylinder that is not being used which could end up in the crankcase.

I told you how. A faulty injector that stays open "leaking injector" will definitely cause fuel on oil.

 

[PEO]

In reading all of this, I think if i had a leaking injector, I would have a lot of black smoke on start up. As I put in my initial listing, I don't see any unusual exhaust. I always watch that for some reason. And the oil that I drained out does not appear to be overly diluted as i feel it would be if fuel was infiltrating into the crankcase. I will go back to the shop tomorrow and recheck the oil that I saved when I drained it and also check the hydraulic oil - but missing a quart is difficult to judge through the sight hole.

In a quick check, I looked at the parts diagram and assume the seal 050 in the picture is culprit that
PoTreeBoy is referring to.

If i do suspect fuel, I will start with the lift pump... simple test.

I will throw something out as a question on this -- I have not been back to the shop since I started this thread. I read in the owners manual of an electric engine shutoff. Obviously that would be a solinoid as shown in the parts manual. However, I do not think mine has the solinoid (thanks to previous owners) and I use the pull lever to kill the engine. IF I push the KILL LEVER in after the engine has stopped - and key off -- would that allow fuel to flow into the injectors and into the engine? I think I have answered it with No excessive black smoke on start up...but wondering........

 

[North Idaho Wolfman]

In a quick check, I looked at the parts diagram and assume the seal 050 in the picture is culprit that
PoTreeBoy is referring to.

Yes 050 is the seal:
31381-76390

Do not open the rest of the pump, as you really can't do much in there.
If you pull the seal out and the shaft has play in it, the pumps probably shot.
Give a shout out and I can tell you more.

IF I push the KILL LEVER in after the engine has stopped - and key off -- would that allow fuel to flow into the injectors and into the engine? I think I have answered it with No excessive black smoke on start up...but wondering........

No not at all, the electric stop solenoid only pulls the stop linkage (same as pulling the stop rod) for about 5 second then it returns to the run position.

If the injectors were bad enough to leak you would know it as you would have a really hard start, you would have black smoke and it would run really bad.
Your model uses pencil injectors they are very tough and work for a long time.

Look on the side of the engine just under the injection pump, alot of them quit working because the timer goes bad.

 

[PEO]

Thanks to all that responded. Wolfman and PoTreeBoy--You Nailed it-but I took the difficult route first.

Because those that smelled the oil I took out and did not smell diesel and the transmission was a little low I took the more difficult route of replacing the hydraulic pump seal. The WSM says the pump is held in with 3 cap screws. However they did not mention the oil lines and o-rings that had to be removed to get the pump out. This was a great time to replace the ragged rubber oil pick up line. That was by far the worst part.

All back together and headed out for more grading. After only a couple of hours it was obvious that did not fix the issue as the oil was growing up the dipstick. Next option was to pull the fuel lift pump. The problem was instantly found. Diesel was dripping from the plunger end of the pump. This was a great time to do some long overdue preventative maintenance and replacing the fuel lines.

Everything back to gether and bled the lines, old orange fired on the first crank. It is amazing that she ran as well as she did as there was very little suction or output pressure in the original fuel pump.

Again, thanks to all - this is a super site for knowledge. I hope this may help the guy with a similar posting i came across a few days ago. The fuel pump is an easy test item.