fuel in engine oil multi fuel motor

[Joe Phillips]

fuel in engine oil multi fuel motor. Anyone know why??

I am getting a fair amount of fuel in my oil on my multifuel motor. Anyone have any ideas why? I am running diesel.

 

[simp5782]

Injection pump leaking over or piston rings failing. Aren't but two spots for fuel on that engine to mix with oil.

 

[drivebymashing]

I use engine oil for fuel. I guess the only way I would know if i had that problem it would show too high on the stick.

 

[Joe Phillips]

Ok thank you for the input.. I truly know next to nothing about these motors. How would I troubleshoot the problem.. Its bad enough if its the pump but if its the rings I would need to rebuild or find another motor. I think the pump costs as much as a whole motor..

 

[gringeltaube]

Hera are a few threads about just that topic:

• http://www.steelsoldiers.com/showthread.php?88982-Mechanical-Booster-Pump-quot-making-oil-quot
• http://www.steelsoldiers.com/showth...uel-crankcase-full-of-fuel-please-advise-over
• http://www.steelsoldiers.com/showthread.php?17961-Question-about-diesel-fuel-in-the-crankcase

G.

 

[Flyingvan911]

Does your 5 ton have a flame heater for the intake manifold? Several of us had to unhook the fuel lines from ours because even though it goes to the intake, if it leaks it will somehow get the fuel into the crank case.

 

[jasonjc]

Or a leaking FDC. What 5 ton and eng do you have?

 

[dmetalmiki]

Does your deuce have a flame heater for the intake manifold? Several of us had to unhook the fuel lines from ours because even though it goes to the intake, if it leaks it will somehow get the fuel into the crank case.

Look to this fault as mentioned this is usually a "good!" source of fuel entering the engine block. If your engine starts and runs good it is not (in the least) the rings.
Also try researching some of the previous posts on this problem, there are quite a few pointers (and fixes) there.

 

[Joe Phillips]

Thank you all.. I now have plenty to check on and thanks to you all I know where to look.. I'm not the greatest mechanic but I'm not the worst either and I can follow directions. Due to overtime and rotating shifts it will probably take me a week to get this stuff checked. I have a 1968 kaiser/jeep m51a2 ldt multifuel spicer 5 speed single sixes 295/85/20's. It does have the flame heater and it failed so I got another from Brad, he said to disconnect it, I had no idea what it was or did so I put it back in. It was there from the factory.... I will now disconnect it. I have the fdc thingy also no idea how it does its thing but will also disconnect it. Again Brad said to disconnect it, but disconnecting something you have no idea what it is or does isn't always the best course of action. Lets see my truck runs great so hopefully its not the rings. Thanks again Joe
I made a mistake on the motor it is a lds 465 1a rebuilt in 1983 Today 6/22/2016 I changed the oil and looked at what I thought I might need to do to bypass the flame heater, and the fdc..

 

[mdemars03]

I had a 1965 Kaiser M52A2 that did the same thing. I had a LDS-465-1A multifuel motor. I noticed a drop in oil pressure on the gauge and white smoke from the exhaust. My experience was the injection pump. The seals on it were bad and so it was leaking fuel into the oil. When I did an oil change there was a total of about 10 gallons of liquid that drained from the case and it was a very watery consistency and smelled like diesel. I pulled the injection pump and had it rebuilt and my problems went away. It cost me around $700 to have it rebuilt but I also ended up having some broken gears inside of the pump. If the pump is bad have it rebuilt and then read the TM for installing it as you have to have the injection pump correctly timed to the motor. It is not a simple remove and replace. I believe the removal, installation, and timing adjustment is all covered in TM-9-2815-204-35 Field and Depot Maintenance for Engine, Diesel, (Multifuel)

As far as some of some of the other parts on the motor... if it turns out to be the injection pump, when you get it rebuilt you can have the FDC bypassed. You only need that if you plan in running WMO or some other fuel other then diesel. If you only plan on running diesel then I would have it bypassed as it is just another part that could cause problems down the road.

The flame heater can be disconnected and the lines removed as it is not needed unless you plan on doing a lot of starting and driving during cold weather. The intake flame heater can cause fuel to get into the oil but is less likely than a bad IP or bad rings. I would disconnect it personally so you remove one source of fuel entering the engine that you dont need. Disconnect the fuel lines and the pump. Your intake flame heater is compromised of fuel lines, a fuel heater pump, and an ignition source. The basic operation is to spray fuel into the elbow area of the intake manifold where it is ignited causing a flame inside the intake manifold to heat the air before it gets to the combustion chambers. The flame heater assembly is covered in TM-9-2815-204-35 Field and Depot Maintenance for Engine, Diesel, (Multifuel).

The TM can be found on this site under the Technical Manuals forum, 5 Ton and Up section, M39 series trucks

http://www.steelsoldiers.com/showthread.php?77614-TM-s-for-the-M39-Series-5-ton

Read up not only on the operators manual but the maintenance manuals. Trust me, the more you know and learn about these trucks, and the more work you do on your own will help tremendously if you end up broken down on the side of the road. It happened to me and I was able to get things fixed and back on the road safely.

 

[mdemars03]

And just for your knowledge, the FDC is the Fluid Density Compensator. It's what helps the injection pump run fuels other than diesel (waste motor oil or WMO) through the system to allow it to get in the combustion chambers correctly.

 

[gimpyrobb]

And just for your knowledge, the FDC is the Fluid Density Compensator. It's what helps the injection pump run fuels other than diesel (waste motor oil or WMO) through the system to allow it to get in the combustion chambers correctly.

That is in-correct.

It does nothing but restrict the power output of your motor. The piston design and intake system make it a multifuel. For all practical purposes, the FDC is useless to us.

 

[red]

Been covered many times in the deuce sections. If your truck has the multifuel engine the FDC is most likely leaking internally, letting diesel flow into your engine oil pan.

Been covered even more is that the FDC DOES NOT affect the engines ability to run other fuels such as oil, veggy oil, gasoline..... All the FDC does is restrict how much fuel will flow through the injection pump, to provide a similar amount of power from the motor regardless of what fuel is being burned. When you bypass the FDC it defaults to maximum flow, a slight power increase when running any fuel other than gasoline.

 

[mdemars03]

I must have missed understood the article I read on FDC so I apologize there. Here is what I had read on FDC's:

The multifuel engine operates on a variety of fuels that have a broad range of viscosities and heat values. These variations in the fuels affect engine output. Because it is unacceptable for the power output of the engine to vary with fuel changes, the multifuel engine is fitted with a device known as a fuel density compensator (fig. 5-3. The fuel density compensator is a device that serves to vary the quantity of fuel injected to the engine by regulating the full-load stop of the fuel pump. The characteristics of the fuels show that their heat values decrease almost inversely proportional to their viscosities. The fuel density compensator uses viscosity as the indicator for regulating fuel flow.

The last line is the main part I had looked at for the FDC beige part of what hales the motor wunderkind fuels other than diesel.

 

[gringeltaube]

What you have read is correct. Now compare this to what you wrote in post #11, 2nd sentence...

 

[dmetalmiki]

Absolutely correct, Summed up completely correctly and succinctly. Nothing amiss in your post#2 or the follow up post. These systems are NOT "junk simple treat em' any old how mechanisms" they ARE extremely complex and quite (actually) beyond the ken of ordinary folk. soz..my rant and 5 1/2 penne'th

 

[gimpyrobb]

I must have missed understood the article I read on FDC so I apologize there. Here is what I had read on FDC's:

The multifuel engine operates on a variety of fuels that have a broad range of viscosities and heat values. These variations in the fuels affect engine output. Because it is unacceptable for the power output of the engine to vary with fuel changes, the multifuel engine is fitted with a device known as a fuel density compensator (fig. 5-3. The fuel density compensator is a device that serves to vary the quantity of fuel injected to the engine by regulating the full-load stop of the fuel pump. The characteristics of the fuels show that their heat values decrease almost inversely proportional to their viscosities. The fuel density compensator uses viscosity as the indicator for regulating fuel flow.

The last line is the main part I had looked at for the FDC beige part of what hales the motor wunderkind fuels other than diesel.

What that means is, the fdc restricts how much diesel is sent to the IP so its power is the same when you use low BTU fuels(and the fdc is all the way open), essentially choking all the possible power you could have.