fuel in my oil/oil pressure low

[wild_willy]

I was wondering if some one could give me some info on the motor problem on my deuce . Its has a 465 cu inch white motor when I started it up oil pressure is good but one the temp goes up the oil pressure drops and there is lots of oil coming out of the blow by tube and I think I have diesel in my oil pan , so need to know if its the injection pump or a injector . Thanks

 

[Jeepsinker]

How low does the oil pressure drop to?

 

[Rmtaunton]

And if you have diesel in oil bypass FDC

 

[RAYZER]

Sounds like your crankcase is full of diesel! Sometimes it's the HH orings gone bad.

 

[Jeepsinker]

Do not drive the vehicle with fuel in the oil.

 

[cattlerepairman]

There are a few reasons why this could happen, such as a leaking flame heater nozzle, the O-rings in the hydraulic head, the fuel density compensator. Search for "Deuce making oil" to get started.
If you need help with searching, look at this: http://bit.ly/1wfnG4i

 

[mhassett]

BY pass the FDC. Leaking between the FDC and the oil.
MHassett

 

[Floridianson]

As said FDC, Boost pump on the side of IP, Oring lower on HH and the Oring on the fuel control assembely. One would think that the flame heater could leak and yes it will add fuel to the intake manifold but one would think it would coat the intake manifold and go in to the cylinders when the intake opens. One would think from there is would just add to the mix and burn or show signs of excessive smokeing at idle. Not too say that it can not get in to the oil pan just saying.

 

[Wildchild467]

As said FDC, Boost pump on the side of IP, Oring lower on HH and the Oring on the fuel control assembely. One would think that the flame heater could leak and yes it will add fuel to the intake manifold but one would think it would coat the intake manifold and go in to the cylinders when the intake opens. One would think from there is would just add to the mix and burn or show signs of excessive smokeing at idle. Not too say that it can not get in to the oil pan just saying.

I totally agree. I never understood how people think a leaking flame heater can cause fuel to get in the oil. It's not even connected. I don't mean that to sound like I am putting down other people and what they think, I just don't understand how it can physically happen. I agree on the possible smoke but still not likely.

 

[Wildchild467]

I was wondering if some one could give me some info on the motor problem on my deuce . Its has a 465 cu inch white motor when I started it up oil pressure is good but one the temp goes up the oil pressure drops and there is lots of oil coming out of the blow by tube and I think I have diesel in my oil pan , so need to know if its the injection pump or a injector . Thanks

Your engine is 478 CID, not 465. Just a friendly FYI

My money is on bad Hydraulic Head o-rings. Its not a terrible job to do. While you are there, replace the stop o-ring also others have mentioned in this post.

 

[Floridianson]

My bet is FDC not bypassed.

 

[Floridianson]

Tom you think the intank pump has enough pressure to show us if the boost pump seal has gone bad? I have not had any problems with the boost pump seal yet and done no testing. My thought was if we park the Deuce nose high and motor off take out the bottom drain plug from the IP and drain out what oil has gathered then turn on the intank pump and see if the boost seal is leaking. We would have to make shure it was not HH orings first. Thoughts

 

[Wildchild467]

I would go after the hydraulic head o-rings first. They like to flatten out over time. From my experience it has been the most common cause of fuel in the oil other than FDC bypassed.

If the FDC is not bypassed, do that first.

If the FDC is bypassed, replace the o-rings on the HH.

MY M109A3 was leaking fuel in the oil and my HH o-rings were flattened out. New o-rings and then I never had a problem after that.

Changing the seal on the boost pump is a pain. You cant get it out easily and I wouldn't go after that right away. I feel strongly on the HH o-rings. Your method of pulling the plug on the back of the injection pump is a good idea, but you would be there forever since the oil would be draining out and you might get fuel confused with oil and visa versa. It might be hard to tell anything from that. the seal on the boost pump is pretty much just a lip seal, not meant to hold any real high pressure. This video on youtube shows a guy pressurizing his boost pump to 60PSI with air and showing the seal leak... But i do not think that that is an accurate "real life" test to check if the seal is leaking. Lips seals are not meant to hold pressure like that. The correct test I think he should have done is to spin the shaft somehow like it would be in the injection pump and pump diesel with it. Then have a 60 PSI pressure relief valve so the pump is constantly pumping 60 PSI. That would be the exact scenerio that the truck would see and yield more accurate results.

Here is the video that I think is not an accurate test for the boost pump seal (just in case you want to see it)

https://www.youtube.com/watch?v=Q0gxynQiOU4

 

[74M35A2]

I would go after the hydraulic head o-rings first. They like to flatten out over time. From my experience it has been the most common cause of fuel in the oil other than FDC bypassed.

If the FDC is not bypassed, do that first.

If the FDC is bypassed, replace the o-rings on the HH.

MY M109A3 was leaking fuel in the oil and my HH o-rings were flattened out. New o-rings and then I never had a problem after that.

Changing the seal on the boost pump is a pain. You cant get it out easily and I wouldn't go after that right away. I feel strongly on the HH o-rings. Your method of pulling the plug on the back of the injection pump is a good idea, but you would be there forever since the oil would be draining out and you might get fuel confused with oil and visa versa. It might be hard to tell anything from that. the seal on the boost pump is pretty much just a lip seal, not meant to hold any real high pressure. This video on youtube shows a guy pressurizing his boost pump to 60PSI with air and showing the seal leak... But i do not think that that is an accurate "real life" test to check if the seal is leaking. Lips seals are not meant to hold pressure like that. The correct test I think he should have done is to spin the shaft somehow like it would be in the injection pump and pump diesel with it. Then have a 60 PSI pressure relief valve so the pump is constantly pumping 60 PSI. That would be the exact scenerio that the truck would see and yield more accurate results.

Here is the video that I think is not an accurate test for the boost pump seal (just in case you want to see it)

https://www.youtube.com/watch?v=Q0gxynQiOU4

That video was definitely not shot in your garage T-Bone!

 

[Wildchild467]

That video was definitely not shot in your garage T-Bone!

Not MY video and the definate give away.... this guy has a work bench and its CLEAN!!

 

[deathrowdave]

Hyd. Head first also, then Flame heater . Flame heater will majorly fill crankcase with fuel. I found this the hard way !

 

[WantOne]

I had the same issue and still have not fixed the problem, bypassed FDC, replaced the rings on flame heater, replaced O-rings on HH and shut off. Next on the list is the boost pump seal.

 

[todds112]

Hyd. Head first also, then Flame heater . Flame heater will majorly fill crankcase with fuel. I found this the hard way !

I get the others and see the path for the fuel to get into the crank case. How can fuel go from the flame heater to the crank case? Since it's on the intake wouldn't it have to go into the cylinders and leak down past thing rings, or am I missing something.

 

[deathrowdave]

Flame Heater

Disconnect the flame heater outlet going to the intake with the engine running . It will be flowing a large stream of fuel if it is leaking through . If no fuel that is not the issue . I purchased a new one from Memphis it leaked through just as bad as a old one , Memphis send a second one . It was good to go ! Good luck

I get the others and see the path for the fuel to get into the crank case. How can fuel go from the flame heater to the crank case? Since it's on the intake wouldn't it have to go into the cylinders and leak down past thing rings, or am I missing something.

 

[doghead]

You can visually identify any of the suggested problem areas.

Do not just change things and hope. You can easily diagnose all of the items mentioned.

The HH, remove the shutoff cover and turn on the in tank pump and you will see if the HH orings or tappet shaft are the issue.

The FDC, remove the bolts holding it onto the housing and turn on the in tank pump, look for leaks underneath it.

The Boost pump, the same.

The flame heater, can only let fuel into the oil if the it leaked enough to fill the intake side housing up to the shaft height and it wept past the sealed shaft and then ran into the oil return port. 99.95 % unlikely(nearly impossible). Flame heater nozzles are known to drip and can be repaired with new o rings. Remove the intake tube and look at the turbo impeller, if it looks to be soaked and fuel runs out when you remove the intake tube, that would show a total failure and possible point of fuel introduced to the oil. This is very unlikely and not one person has ever had this happen(and post it on this site in about 7 years). Personally, I would not even consider this a possibility.