Fuel in my oil?
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From: Milwaukee,WI
Fuel in my oil?
My nephew just had a new injection pump ,lift pump and his turbo rebuilt last week. Today he had oil coming from an overflow,and found alot of fuel mixed with the oil. What do you guys-girls make of this?. It was repaired at a very reputable diesel shop. And its sitting there now, until Monday.Its a 2001 24 valve with 140000 miles
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From: League City, TX
The lift pump will not ever pump fuel into the oil. The lift pump is an electric pump mounted on the engine block.
The most likely cause of fuel in the oil is an injector that is locked open, dumping in excessive fuel. My advice is to pull the injectors and inspect them, and have them tested. Have that done as soon as possible to avoid burning up a piston, and possible cylinder damage. As well as bearing damage, since fuel (although slippery, and technically a fuel oil) does not do a very good job lubricating engine parts. Good luck, and hope it it turns out well.
The most likely cause of fuel in the oil is an injector that is locked open, dumping in excessive fuel. My advice is to pull the injectors and inspect them, and have them tested. Have that done as soon as possible to avoid burning up a piston, and possible cylinder damage. As well as bearing damage, since fuel (although slippery, and technically a fuel oil) does not do a very good job lubricating engine parts. Good luck, and hope it it turns out well.
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From: Mount Juliet, TN
Sounds like an injector is stuck open. Pull them and have them inspected and tested like jr said. Do not start the engine like this. You can spin a bearing in no time. Could there be a leak between the line going into the head and the injector? Just one more place to look. I don't think there is anywhere else fuel could get into the oil.
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From: Edmonton Alberta
Isnt there a seal in the front of the injection pump that can go causing the IP to dump fuel into the crank case. I dont think a stuck open injector will do it as the "extra" fuel is only injected on the compression stroke anyway so if anything it will show up as black smoke when the engine is hot and excessive white/blue on a cold start, besides the engine would have a miss as the open injector cannot inject the fuel in at the desired pressure (read injector causes pressure, not the pump).
Not sure as well but the returned fuel travels thru the head and around the injector if one was not seated it could leak into the crankcase, again not sure of this theory as I have not worked on the injectors of my truck yet.
On a side note I've worked on Canadian Military APC's (armoured Personell Carriers) for 8yrs or so,about 12yrs ago they had a 6V53 detroit it was a 2 stroke diesel and was prone to leaks especially crossover tubes, they would dump fuel into the crankcase, the oil was so deluted that it would come out like water(looked like it too!) we never lost many engines from blowing a rod or crank, but I changed more from burning coolant. anyway I think your bottom end will be fine, we used to put a dye in the fuel that would help pinpoint the leak within seconds, not sure where you can get it but you might see if the UV die is fuel compatiable, I'm 99.9% sure that it is. with the valve cover off and the engine running a UV light should find the leak pretty quick if its leaking under the valve cover, as it should show up near or around the injectors if all the sudden it looks like the oil is turning color (because of the UV light) then I'd say the "new" IP is leaking.
Not sure as well but the returned fuel travels thru the head and around the injector if one was not seated it could leak into the crankcase, again not sure of this theory as I have not worked on the injectors of my truck yet.
On a side note I've worked on Canadian Military APC's (armoured Personell Carriers) for 8yrs or so,about 12yrs ago they had a 6V53 detroit it was a 2 stroke diesel and was prone to leaks especially crossover tubes, they would dump fuel into the crankcase, the oil was so deluted that it would come out like water(looked like it too!) we never lost many engines from blowing a rod or crank, but I changed more from burning coolant. anyway I think your bottom end will be fine, we used to put a dye in the fuel that would help pinpoint the leak within seconds, not sure where you can get it but you might see if the UV die is fuel compatiable, I'm 99.9% sure that it is. with the valve cover off and the engine running a UV light should find the leak pretty quick if its leaking under the valve cover, as it should show up near or around the injectors if all the sudden it looks like the oil is turning color (because of the UV light) then I'd say the "new" IP is leaking.
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From: Milwaukee,WI
I kinda thought that this might be related to the new IP,and that is why I posted here. I'm not very knoweldgeable in this stuff.I have a pretty good Idea of how it all works and I'm an excellent parts replacer but I'm no Mechanic.It's just one of those things,you know"I just had my oil changed and now my radio don't work! What did you do?" I guess I don't know if fuel in the oil and the new IP have anything to do with each other.But I would have thought that the truck would run like garbage with a stuck injector.
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From: East Millsboro, PA.
Some guys like to pull the injector lines so that they are out of the way to install a new IP. Possibly could have cracked a connector tube by overtightening the lines. To me it sounds like the IP seal may be blown out in the front of the pump as mentioned because they shouldn't have messed with the lines near the tubes. A stuck injector would show its face by overfueling & rough idle with lots of smoke.
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From: League City, TX
Nick,
I don't think there is an injector return line for our injectors (i may be wrong). I do know there is a return line for the pump itself.
The VP44 does not draw any oil from the engine for lubrication (unlike the P7100 on the 12V). It might leak through the front seal into the timing case/crankcase. However that is unlikely and not a common failure (if at all). I don't know if fuel is that far forward in the VP44.
The prime purpose of the valve in the injector is to build up pressure until it "pops" (the pop pressure), which is somewhere around 4,000 PSI. The prime reason for that is when you have really high pressure, trying to come out of a set of tiny holes in the injector tip, it creates jets of extremely fine mist (atomization) of the fuel. That allows it it to burn good.
When an injector is stuck open, the pressure cannot build up like it should. What happens here is that the fuel is still injected, but it is more squirted in. Since the fuel is not properly atomized, you will have an incomplete burn. The excess fuel then collects on the piston. Some of it goes out on the exhaust stroke, but a majority seeps down pasts the rings, and into the crankcase where it ends up in the oil.
The important thing to remember is the VP44 only injects the amount of fuel needed, based upon what the sensors and and driver's foot are telling it to, because its a rotary style injection pump. With that, the EGTs may be slightly higher, but won't have a lot of black smoke because of the incomplete burn. The real danger here is fuel burning on the piston itself, which will quickly ruin a piston. When working normally, the combustion flame front doesn't contact the piston, rather the pressure wave from the combustion process forces the piston down.
This is more of a problem on the newer common rail engines, since the injector has a steady supply of high pressure fuel, and will constantly inject fuel. They will fill the crankcase a lot faster.
I don't think there is an injector return line for our injectors (i may be wrong). I do know there is a return line for the pump itself.
The VP44 does not draw any oil from the engine for lubrication (unlike the P7100 on the 12V). It might leak through the front seal into the timing case/crankcase. However that is unlikely and not a common failure (if at all). I don't know if fuel is that far forward in the VP44.
The prime purpose of the valve in the injector is to build up pressure until it "pops" (the pop pressure), which is somewhere around 4,000 PSI. The prime reason for that is when you have really high pressure, trying to come out of a set of tiny holes in the injector tip, it creates jets of extremely fine mist (atomization) of the fuel. That allows it it to burn good.
When an injector is stuck open, the pressure cannot build up like it should. What happens here is that the fuel is still injected, but it is more squirted in. Since the fuel is not properly atomized, you will have an incomplete burn. The excess fuel then collects on the piston. Some of it goes out on the exhaust stroke, but a majority seeps down pasts the rings, and into the crankcase where it ends up in the oil.
The important thing to remember is the VP44 only injects the amount of fuel needed, based upon what the sensors and and driver's foot are telling it to, because its a rotary style injection pump. With that, the EGTs may be slightly higher, but won't have a lot of black smoke because of the incomplete burn. The real danger here is fuel burning on the piston itself, which will quickly ruin a piston. When working normally, the combustion flame front doesn't contact the piston, rather the pressure wave from the combustion process forces the piston down.
This is more of a problem on the newer common rail engines, since the injector has a steady supply of high pressure fuel, and will constantly inject fuel. They will fill the crankcase a lot faster.
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From: Santa Fe TX
Fuel can leak out the front seal on the VP44 I had it happen to me it filled up the crank case with fuel I drained 8 Gallons of Fuel oil mix out of my engine.
What is the fuel pressure? My problem was caused by too much FP 25psi+ and actually pushed the seal out at the shaft end of the VP44
I would bet your problem is with this seal
What is the fuel pressure? My problem was caused by too much FP 25psi+ and actually pushed the seal out at the shaft end of the VP44
I would bet your problem is with this seal
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From: League City, TX
Fuel can leak out the front seal on the VP44 I had it happen to me it filled up the crank case with fuel I drained 8 Gallons of Fuel oil mix out of my engine.
What is the fuel pressure? My problem was caused by too much FP 25psi+ and actually pushed the seal out at the shaft end of the VP44
I would bet your problem is with this seal
What is the fuel pressure? My problem was caused by too much FP 25psi+ and actually pushed the seal out at the shaft end of the VP44
I would bet your problem is with this seal
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Hey guys thanks for all the info. I am the nephew of bumpy truck. Like he said I took the truck to one of the most reputible shops in the area, but I still need to be armed with some knowledge and education because currently I know next to nothing about this stuff. Thanks again
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From: Cedar Grove, New Jersey
first off, stop driving it, and get thoses injectors checked, if you absolutely have to drive it, drain your oil and re fill with motor oil, at least you will have more oil than fuel in there for a little bit.
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From: League City, TX
Hey guys thanks for all the info. I am the nephew of bumpy truck. Like he said I took the truck to one of the most reputible shops in the area, but I still need to be armed with some knowledge and education because currently I know next to nothing about this stuff. Thanks again
). Unless there is problems with the engine running, the injectors do not normally require any servicing. They require having the valve cover taken off to even get to the injectors, then remove the hold downs, to even pull it out. Like I said before unless there is a need to service or replace them, they normally don't get touched.
Here is a picture for you so you can get an idea of how to get to them. I took this picture when I set the valves on my engine. It shows the top of the head, with the valve cover off. From background to foreground in this picture, you can see the valve sets for cylinders # 6, 5, and part of 4.
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From: Edmonton Alberta
Nick,
I don't think there is an injector return line for our injectors (i may be wrong). I do know there is a return line for the pump itself.
there is, its called a Fuel drain manifold, a drilled passage thru the head (14-86 in the FSM) it exits the rear of the head and is connected to the fuel return line via a "T" fitting
The VP44 does not draw any oil from the engine for lubrication (unlike the P7100 on the 12V). It might leak through the front seal into the timing case/crankcase. However that is unlikely and not a common failure (if at all). I don't know if fuel is that far forward in the VP44.
gonna look for a internal diagram to confirm fuel near the seal, although another poster has confirmed that it can happen due to excessive LP pressure, I think a bad seal instal could net the same results, FWIW the VW diesel uses a Bosch rotary style pump as well and hi-mileage units do leak too, but again, I agree its not common, but possible
The prime purpose of the valve in the injector is to build up pressure until it "pops" (the pop pressure), which is somewhere around 4,000 PSI. The prime reason for that is when you have really high pressure, trying to come out of a set of tiny holes in the injector tip, it creates jets of extremely fine mist (atomization) of the fuel. That allows it it to burn good.
No problem with this
When an injector is stuck open, the pressure cannot build up like it should. What happens here is that the fuel is still injected, but it is more squirted in. Since the fuel is not properly atomized, you will have an incomplete burn. The excess fuel then collects on the piston. Some of it goes out on the exhaust stroke, but a majority seeps down pasts the rings, and into the crankcase where it ends up in the oil.
I agree with improper burn but not with the extent of washing down a cyl like on a gasser, and if it did it would need to be run lots to show up in the oil, the heat of compression will still burn the fuel albiet not well and I do believe there will not be enough left over to wash past the rings. For the amount of fuel he is showing in his oil it has to be a large leak, fuel acculimation via bad injector would take thousands of miles. (imagine how many tablespoons of fuel it would take to dilute 11 qts of engine oil, and that would only be if it was possible to have 1 tablespoon of oil get by the heat of compression and rings per engine revolution. Using tablespoons of fuel as a reference would likely be thousands times more than what is actually being injected at one time, I just used it to show how small the relationship of fuel to oil is. I think the poor engine performance would over shadow the leak, and he claimed no performance/drivability issues
The important thing to remember is the VP44 only injects the amount of fuel needed, based upon what the sensors and and driver's foot are telling it to, because its a rotary style injection pump. With that, the EGTs may be slightly higher, but won't have a lot of black smoke because of the incomplete burn. The real danger here is fuel burning on the piston itself, which will quickly ruin a piston. When working normally, the combustion flame front doesn't contact the piston, rather the pressure wave from the combustion process forces the piston down.
Yes the piston could have a hole burned thru it, but not from an open injector, but from one with a bad spray pattern, as when that happens it acts just like a cutting torch. a open injector would only allow a small amount of fuel to dribble out. page 14-95 FMS also states an open injector will cause black smoke and missfiring
This is more of a problem on the newer common rail engines, since the injector has a steady supply of high pressure fuel, and will constantly inject fuel. They will fill the crankcase a lot faster.
I don't think there is an injector return line for our injectors (i may be wrong). I do know there is a return line for the pump itself.
there is, its called a Fuel drain manifold, a drilled passage thru the head (14-86 in the FSM) it exits the rear of the head and is connected to the fuel return line via a "T" fitting
The VP44 does not draw any oil from the engine for lubrication (unlike the P7100 on the 12V). It might leak through the front seal into the timing case/crankcase. However that is unlikely and not a common failure (if at all). I don't know if fuel is that far forward in the VP44.
gonna look for a internal diagram to confirm fuel near the seal, although another poster has confirmed that it can happen due to excessive LP pressure, I think a bad seal instal could net the same results, FWIW the VW diesel uses a Bosch rotary style pump as well and hi-mileage units do leak too, but again, I agree its not common, but possible
The prime purpose of the valve in the injector is to build up pressure until it "pops" (the pop pressure), which is somewhere around 4,000 PSI. The prime reason for that is when you have really high pressure, trying to come out of a set of tiny holes in the injector tip, it creates jets of extremely fine mist (atomization) of the fuel. That allows it it to burn good.
No problem with this
When an injector is stuck open, the pressure cannot build up like it should. What happens here is that the fuel is still injected, but it is more squirted in. Since the fuel is not properly atomized, you will have an incomplete burn. The excess fuel then collects on the piston. Some of it goes out on the exhaust stroke, but a majority seeps down pasts the rings, and into the crankcase where it ends up in the oil.
I agree with improper burn but not with the extent of washing down a cyl like on a gasser, and if it did it would need to be run lots to show up in the oil, the heat of compression will still burn the fuel albiet not well and I do believe there will not be enough left over to wash past the rings. For the amount of fuel he is showing in his oil it has to be a large leak, fuel acculimation via bad injector would take thousands of miles. (imagine how many tablespoons of fuel it would take to dilute 11 qts of engine oil, and that would only be if it was possible to have 1 tablespoon of oil get by the heat of compression and rings per engine revolution. Using tablespoons of fuel as a reference would likely be thousands times more than what is actually being injected at one time, I just used it to show how small the relationship of fuel to oil is. I think the poor engine performance would over shadow the leak, and he claimed no performance/drivability issues
The important thing to remember is the VP44 only injects the amount of fuel needed, based upon what the sensors and and driver's foot are telling it to, because its a rotary style injection pump. With that, the EGTs may be slightly higher, but won't have a lot of black smoke because of the incomplete burn. The real danger here is fuel burning on the piston itself, which will quickly ruin a piston. When working normally, the combustion flame front doesn't contact the piston, rather the pressure wave from the combustion process forces the piston down.
Yes the piston could have a hole burned thru it, but not from an open injector, but from one with a bad spray pattern, as when that happens it acts just like a cutting torch. a open injector would only allow a small amount of fuel to dribble out. page 14-95 FMS also states an open injector will cause black smoke and missfiring
This is more of a problem on the newer common rail engines, since the injector has a steady supply of high pressure fuel, and will constantly inject fuel. They will fill the crankcase a lot faster.
Good points and we may differ on some things, Dont take me wrong I'm not trying to start anything, I'm on this board as well to soak up all the nuances of the dodge/cummins. And for that I'm grateful no sense in trying to re-invent the wheel when folks on this board have found out what works and what does not.
I dont have much cummins specific experience, but do have lots of "other" experence to draw on and share.