Question about diesel fuel in the crankcase

[vlmuke]

I have a mulitfuel duece it is getting diesel fuel in the the crankcase I was told that it is coming from the injector pump I know FDC is bypassed is there any other thing that would cause fuel to get into the crankcase?? if it is the injector pump does anyone know of source to have them rebuilt any ifo or advice would be appreciated
Thanks
Rich

 

[FreightTrain]

how much fuel and how many miles was it run?If there was a whole lot of fuel in the oil and another whole lotta miles then there may have been damage to the bearings.As for IP replacement.You can buy a good running engine(or in my case,a whole dang truck!) for the price of a rebuilt pump.(around 1100 bucks).i would find someone with a known good used pump though.Usually can be had for around $250-$350.

 

[FreightTrain]

are you absolutly sure the FDC has been bypassed?

 

[vlmuke]

yeah I'm sure as I posted pic of it back in august and everyone replied that it was by passed and there is also a sticker on it saying it was bypassed by toole aremy depot I changed the oil last spring right now it reads over full and it only had maybe 50-100 miles on it

So then you would agree that the only source for diesel to enter the crankcase would be through the injector pump

 

[WillWagner]

Or a flame heater if it is hooked up. Most likely a pump.

 

[underdog]

A bad injector will fill a crank case.

 

[jasonjc]

When are you checking the oil?? hot or cold? Do you smell fuel in the oil?

 

[vlmuke]

I have done both what spurred it was when I changed the oil there was about a gallon extra of oil and it was thinner that it should have been and yes it smelled really strong of diesel when I checked the oil lately the crank case is getting fuller and fuller each time I check it
how can I tell if it is a bad injector? as injectors are cheaper than a new pump would it run poor as it runs decent or would the injector leak down once the engine is off
I would really like to get this fixed with my tax check I have an ste ice unit but have never used it would that help?
any advice would be greatly appreciated

 

[cranetruck]

Re: RE: Question about diesel fuel in the crankcase

Or a flame heater if it is hooked up. Most likely a pump.

Hmm...a leaking flame heater nozzle could create hydrostatic lock, but there is no pressure when the engine is off and any leakage here when the engine is running would mix with the air and burn....unless I missed something...

Make sure there are no fuel lines connected to the FDC.
When I discovered that my FDC leaked fuel into the crankcase, it was at a rate of about 1qt/1,000 miles, nothing like what you are talking about....

Maybe the gear pump (booster pump) on the injection pump...maybe a leaky shaft seal.

 

[vlmuke]

RE: Re: RE: Question about diesel fuel in the crankcase

HMM is that where the leaking occurs can I just repair that piece rather than replace the whole pump??

 

[cranetruck]

RE: Re: RE: Question about diesel fuel in the crankcase

Yes, item "FF" in the image can rather easily be replaced, don't know if that's the leak, though, but if the FDC is out of the circuit, there isn't much left.

 

[Angus1]

RE: Re: RE: Question about diesel fuel in the crankcase

There is an IP on FEE BAY Not mine just found it.
http://cgi.ebay.com/ebaymotors/ws/e...viewitem=&item=150212868815&_trksid=p3907.m29

 

[m-35tom]

RE: Re: RE: Question about diesel fuel in the crankcase

actually there is one major place for a leak that no one ever talks about. there are two 'o' rings under the ip head and they always look old, flat, and hard. the fuel pressure in the base of the ip head is from 20 to 70 psi so you can imagine what may happen. very easy to replace, as i have said in some other posts, there is hardly ever any need to replace the whole injection pump. just replace the head, that is the place where ' it all happens '

 

[cranetruck]

RE: Re: RE: Question about diesel fuel in the crankcase

I'm aware of those O-rings, don't see how they are involved in sealing fuel out, need to take another look....
The spring loaded plunger rides on a cam, no fuel on that side.

 

[m-35tom]

RE: Re: RE: Question about diesel fuel in the crankcase

there is fuel under pressure in the area between the 'o' rings. how do you think the fuel gets to the pump plunger. very easy / likely to have a leak here yet i never see it mentioned.

 

[cranetruck]

RE: Re: RE: Question about diesel fuel in the crankcase

Yes, I agree Tom.

 

[nickd]

RE: Re: RE: Question about diesel fuel in the crankcase

Tom, Where do you get the o rings?

 

[cranetruck]

RE: Re: RE: Question about diesel fuel in the crankcase

IP rebuild kit NSN 5330-00-884-4807 is one place.....

 

[vlmuke]

RE: Re: RE: Question about diesel fuel in the crankcase

I think for starters I will replace the o-rings and go from there
I really appreciate all your help and input