Fuel getting into the oil

[Qapla]

We have a NH TC40D with a front loader and backhoe.

I seems like we may be getting diesel in the crankcase oil - not totally sure, but when we changed the oil today it had far more in there then it should have - and it smelled a bit like diesel. We have also noticed that the fuel does not see to be going as far as it should be - a sign of missing diesel.

Thing is, it seems to run just fine.

Any ideas?

 

[Dave M7040]

Usually it is the mechanical lift pump whose diaphragm is failing allowing diesel to enter the crankcase.
Dont know your specific tractor but on ebay these pumps are less than $50.
See my extensive post on same subject to a John Deere owner.
He later posted that indeed the pump was shot.
Dont ignore this as failed bearings or an engine seizure can result from being lubricated by diesel fuel!!!!
http://www.tractorbynet.com/forums/...3010-oil-dripping-everywhere.html#post4063338
Dave M7040

 

[Qapla]

Follow up ....

We replaced the mechanical lift pump.

Still have the problem. We are still getting fuel in the oil - not just a little, it is filling the oil pan with fuel.

Additional ideas ?????

 

[Harry in Ky]

Does it need to be running to transfer, or will it happen with the engine off? That type pump is not well known for leaking into the crankcase, but who knows?

 

[Leejohn]

fuel injecter pump is next.

 

[Dftodd]

Start checking fuel injectors. One is probably stuck open and over fueling

 

[FredH]

Fuel injector . Either Stuck , Cracked , or the seat is bad .

Been there , done that on a Detroit Diesel .

Fred H.

 

[Dave M7040]

Having been the one to suggest the lift pump, I am disappointed your problem continues.
If there is not excessive black smoke in the exhaust, it seems unlikely that a fuel injector is not sealing or over fueling.
I am with LeeJohn in now suspecting the injector pump. The main shaft for the injection pump enters a gear case at the front of the engine where all the timing functions take place.
If the seal for the injection pump shaft is gone it could be leaking fuel into the front gear case which is connected to the crankcase.
I am not familiar with your engine but in most cases the injection pump needs to be timed after removal to insure the fuel is injected at the correct place in the engine cycle.
Sometimes a special tool is needed to do the timing.
You could remove the pump and take it to a service facility which specializes in injectors and pumps. They can quickly tell you if there is a problem with the seal.
Re-installing the pump is the tricky part and you should either get a shop manual or find someone who knows how to do it so you don't cause any damage.
Having the injectors serviced at this time would be prudent. If you had the time I would even have the injectors serviced first and if there are no major problems then move on to the injection pump as doing the injectors is the easy part.
Plse keep the post updated as we will all learn from you on this.
Dave M7040

 

[Qapla]

From what we can determine, the fuel only gets in while the tractor is running ..... and, it takes a while. It doesn't happen all at once or as soon as we crank it up - but, if we work all day we will have about half an oil pan full of oil.

 

[Qapla]

Update

We changed the oil yesterday and what came out was full of fuel We put in fresh oil and ran the tractor for a short while. It ran fine and it was hard to tell if we were getting fuel in the oil but we think it was.

We shut it down before any damage could occur. Only thing is, we forgot to turn the fuel off.

Well, we checked it today and found the fuel gauge is down and the oil pan is completely full ...so, it appears that fuel IS getting in the oil when it is NOT running.

Any new ideas?

 

[Fawken]

As previously mentioned, it is the injectors. And that is the first and easiest thing to check when you have this condition.

 

[Qapla]

In looking at the parts diagram, what parts do we need?

 

[JimRB]

I am voting for the injection pump is leaking into the crankcase. Leaky injectors would make for no start, very black start or hydrolock. Nothing $1,800 wouldn't fix. New Holland TC40D Engine 01.13.03 FUEL INJECTION PUMP ASSEMBLY gives a picture sort of.

 

[Fawken]

I am voting for the injection pump is leaking into the crankcase. Leaky injectors would make for no start, very black start or hydrolock. Nothing $1,800 wouldn't fix. New Holland TC40D Engine 01.13.03 FUEL INJECTION PUMP ASSEMBLY gives a picture sort of.

It might well be, and likely is, but the injectors are the easiest and cheapest thing to check.

 

[Billrog]

I would definitely check the injectors first .

 

[Qapla]

Is the "core injection fuel pump" the individual pump (there are four of them) in the fuel pump assembly?

They are held in with two bolts each that have 5-sided heads. Where can we get the socket/wrench to fit these bolts?

 

[Harry in Ky]

Don't fool with those! They are odd sized for a reason. Remove the entire assembly and send it off to your favorite pump shop. It's not complicated. Turn off the fuel supply, remove the supply line, injector lines, fuel shutoff solenoid, four mounting nuts and lift the pump up a bit. Tilt it outwards a bit and look for the governor link on the back side. Remove the hairpin (without dropping it into the engine) disconnect the link and remove the unit. I wouldn't fool with the injectors at this point because I seriously doubt they any part of your problem. If you decide to do that as well, that's your choice. If I were doing it, I would do the pump first and go from there.

 

[Qapla]

Don't fool with those! They are odd sized for a reason. Remove the entire assembly and send it off to your favorite pump shop. It's not complicated. Turn off the fuel supply, remove the supply line, injector lines, fuel shutoff solenoid, four mounting nuts and lift the pump up a bit. Tilt it outwards a bit and look for the governor link on the back side. Remove the hairpin (without dropping it into the engine) disconnect the link and remove the unit. I wouldn't fool with the injectors at this point because I seriously doubt they any part of your problem. If you decide to do that as well, that's your choice. If I were doing it, I would do the pump first and go from there.

We have no idea who or where to send such a pump - ideas? suggestions?

 

[Harry in Ky]

Surely there's a fuel injection pump shop somewhere in your area. If all else fails, call your local dealer and inquire as to where they send pumps for repair. They may ship it for you.

 

[Joel at CDI]

Don't fool with those! They are odd sized for a reason. Remove the entire assembly and send it off to your favorite pump shop. It's not complicated. Turn off the fuel supply, remove the supply line, injector lines, fuel shutoff solenoid, four mounting nuts and lift the pump up a bit. Tilt it outwards a bit and look for the governor link on the back side. Remove the hairpin (without dropping it into the engine) disconnect the link and remove the unit. I wouldn't fool with the injectors at this point because I seriously doubt they any part of your problem. If you decide to do that as well, that's your choice. If I were doing it, I would do the pump first and go from there.

Very good advice, I would add that you want to make sure to keep track of the shims/gaskets that are under the injection pump mounting flange as these set the pump timing. Since it leaks down while the engine is not running I think you can rule out the injectors being the issue. You most likely have dried out o-rings on the 4 sleeves that are held in by the funky 5 sided bolts. Definitely don't try to remove them yourself as they are slotted for adjustment and are part of a sensitive assembly.