Archived oil in fuel

[ramdriver15]

Hey all for anyone, and mabe mass diesel will chime in... .



found engine oil in he fuel last filter cange. noticed increase in blow by and also extra smoke.



oil pressure when the truck is cold is normal, but once it warms up the gauge says its 0. i mech. gauged this and it was at 40-80..... wondering if there is a seal in the pump that said f-u and is it easy fix or new pump time?



also had a massive knocking noise start tonight

 

[Missouri Mule]

Which pump? The vp44 doesn't have oil running thru it only fuel.



You mite need new oil sending unit.



To get it straight you found oil in your fuel filter?

There is really know way I can think of that oil can get into the fuel unless you pour into the fuel tank on 24 valves now on 12 valves it is a differnt story.



Or is there fuel in your oil?

If it is knocking I would check the oil for fuel in it.



Should of asked which truck?

On the p7100 pump you can take it to authorized bosc shop and have seals replaced (or any shop you feel can do the job right).

 

[ramdriver15]

its on my 96 12v... . told it might be a lift pump leaking

 

[ramdriver15]

YouTube - Cummins knock

 

[Missouri Mule]

Yes have read where a seal on the back of the lift pump will give out letting oil in but I understand it is very rare. Usuallly ticking sound,hard start or fuel leaking out of it are signs of lift pump going.

 

[ramdriver15]

ivcew got a spare injection pump, and lift pump, gonnas try and swapp both. Do one at a time. if one fixes before the other then i know i can stop, or hasve my injection pump rebuilt.

 

[ramdriver15]

Heeeelllllp

here is what i did.



-ran the valves, some were out of adjustment

-checked plunger travel > looked ok to me besides the oil

-Cranked with dvs installed no lines

-Let the truck idle. Cracked each line asll made truck have a dramatic change.

-Note: Truck idles perfectly smooth just loud ticking

-Ran truck with no valve covers, nothing out of the normal here

- No noise when cranking

-perfectly rythmic with idle of engine and speeds up with throttle

-I pulled the lp off the old engine and will swap it soon, taking a break.

-Push the clutch in no difference, no difference if you take off in gear

-Looks to be engine oil in fuel. I dont know where this oil is coming from but its a hazy black floating though. it looks like an outboard mixture, but black oil.

-When truck is warm and throttle is brought up slow it releases a ton of white/blue smoke



To me the noise is coming from the bottom end, but it may be resonationg through the oil pan. It resonates all the way to the drive shaft.

 

[Missouri Mule]

Sounds like the lift pump. I read where it ticks but don't know how loud.

 

[Huff N Puff]

I dont know how you can check for oil in your fuel.

What you are probably seeing is soot or combustion gases getting into the fuel return. Its probably caued by a bad injector, which is also your knock,this will also dump fuel into your oil,which is also your low oil pressure. Crack injector lines one at a time, see if the knock quiets when you crack the injector. That will tell you which injector it is.

 

[Huff N Puff]

The lift pump

its on my 96 12v... . told it might be a lift pump leaking

Will leak fuel into the oil,Its unlikly to leak oil into the fuel. Its is possible,but very unlikly.

 

[ssanders60]

I've seen heavy jelly type grease or oil caught in the fuel filter back

in the mid '80s when I was buying fuel from Russell Oil Co. , also have seen

it in the filters of Locomotives, but not lately.

When I started buying fuel elsewhere, I stopped seeing plugged fuel filters,

which as you know will cause your engine to starve for fuel and run ragged.



Conoco bought Russell.