Oil Fairy?!?!

[Flyingvan911]

The nozzle will leak and let fuel squirt into the intake manifold. No one really knows how the fuel gets into the crankcase but it does. I capped off the two fuel lines going to the nozzle and put a couple of pipe plugs in the nozzle itself.

Look at your intake manifold. You'll see a sparkplug looking thing (igniter) and below it is the nozzle with two fuel lines going in to it.

 

[eagle4g63]

If it is leaking fuel into the intake.............then when the truck is shut down that leak of "extra" fuel can get into the oil past the piston rings. Other than that the IP can leak fuel into the oil.........I would make sure the FDC IS bypassed and not just a sticker was on the oil filter housing that happened to make it to your truck.

 

[doghead]

That is what it is called in the manuals. Yes, I KNOW it is activated by Bowden cable to the dash, right next to the master power switch.

Yes, for the past 100 years, solenoid has earned the definition of linear electromagnetic motor. But it is a French word for cylinder.

Did you know shock absorbers are also called dashpots? And they don't actually absorb electrical shock, much less mechanical. They are dampers with primarily velocity reduction as their purpose.

For future refrence.​

3-21. Repair of Timing Window Cover and Fuel
Shutoff Rod Assembly (All Except Code A Injection​

Pumps)

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The above is from the TM. The A code IP does have an electric solenoid(not the OP's truck).​

I don't see it refered to a solenoid anywhere else in the IP manual.​

 

[searls84]

Dumb question: how does the manifold heater make oil? I can't see anywhere that fuel can enter the oils system. Am I missing something?

Fuel heater runs off whatever is in your fuel tank... Easiest way to eliminate that out of the equation is to bypass it. If you're not wanting to get rid of it though, I would take the two fuel lines off the injector nozzle, remove the nozzle out of the intake, reconnect the two lines to the nozzle, and let it just hang next to the block over night. If that's your problem, the results should be pretty evident.... My personal opinion (I'm definitely no expert by any stretch of the imagination!) is that in order to get 2 more qts of fuel in the oil since the last time you checked, that nozzle would have to one heck of a leak, and some really worn piston rings or seal problems in the heads in order for that much fuel to get from the combustion chamber down into the oil... If my logic here is wrong, please someone chime in! I would be leaning towards the HH orings as the culprit, since your FDC is bypassed.....

 

[doghead]

HH O rings, shut off rod O ring, or booster pump seal.

Each can be visually inspected for leakage with the in-tank pump running.

 

[cpf240]

Maybe you could drop the oil pan and then run it to see where the extra is coming from?

 

[jeffhuey1n]

This is where I'm at so far. The intake fuel nozzle (next to the spark plug) was leaking externally. When I removed it and took it apart I found the o ring was old and cracked. I replaced it and the External Leak from there stopped. I replaced a Fuel line..not sure yet where it goes but it comes off the top of the secondary fuel filter manifold (?). It's a rubber and metal mesh hose that connects to a hard line on the left hand side (drivers side) inboard of the frame.

I pulled the HH using instructions using the search funcion. There is a very good thread there and I'm still using it to do troubleshooting. After getting all the hoses and lines diconneced, I removed the throttle cover and the assorted parts in the way of gettng to see where the red gear tooth was. Took FOREVER getting it lined ALMOST up only to have it go to far and ave to start all over again. Worked till after sundown last night and got too cold. Covered everything up to protect from dirt ad got back to it this morning. Bumped the starter once and poof the red gear tooth lined right up. Since everything was already disconected, it was just a matter of lifting the 6 fuel lines high enough and lifting the HH out. In the bottom of the hole there was a couple parts that didn't belong. They were supposed to be on the end of the shaft; one was a small metal...not sure what it's called and the retainer that was supposed to hold it on the end of the shaft. The O rings (big ones..2+ inches for one and 2 1/2 to 3 inches for the other) were the only o rings readily visible. Neither looked like they needed replacing. Doesn't matter, I don't have new ones to put in their place. Looked over the shaft...nice snug fit. If it's suppoed to keep fuel out of the oil or vice versa, it looks like it's doing its job as there are no rub marks on the metal. I took it as far apart as I could. everything looked clean and undamaged. There are a series of allen head recesed screws around the HH. Couldn't turn them with the tool I had on hand so I didn't go any further. Over all, except for some dirt or rust that had accumulated in the recesses for the fuel lines, everything looked good. The rubber covers for the lines are all rotted and aren't doing a thing except get in the way. I need to put then on the list of things to change out. I've began the process of putting it back together. The HH is back together including the parts that were found in the hole and reinstalled the assembly with red gear tooth lined up correctly. All the fuel lines are connected and the retaining nuts are installed hand tight. Still have to reconnect the rest of the stuff taken off the side of the HH. For now it's covered to prevent dirt contamination Depending on weather, I hope to have it complete and reasy for testing this week.

A couple of extra tips. Remove the heater from the mount. Dsconnect the air hoses and the 4 retaining bolts. Leave the water lines attached and just set it on top the engine out of the way. If you use the starter to move the gear to reach the red gear tooth, fuel dumps. A 5 gallon bucket isn't enough. You need a large drip pan plus the 5 gallon bucket. The bucket catches most of the fuel but with the wind and various other parts in the way, there isn't a direct stream into the bucket. Having the pan catches 99+% of the fuel. I still haven't figured out the fuel heater relation to fuel getting into the crankcase but do have a question about the fuel nozzle. I'll look it up but what is upstream of the nozzle? Is there a shut off valve that stops fuel from draining into the nozzle and on into the fuel manifold? Is there more than one O ring in the fuel nozzle? Things I still need to check out.

That's it for now. Too cold to work more today. If there's good weather in the next few days (they're calling for snow for the next three days at least) I'll get 'er done and let you know how it goes. That fuel nozzle's got my curiosity up. Time to hit the books.

 

[jeffhuey1n]

Just had a thought. The only place where oil and fuel can come into contact with each other is in the turbo. Fuel is injected by the fuel nozzle (see TM 9-2320-361-20, paragraph 3-31, page 3-67, item 27). Oil is injected by the oil inlet tube and drains out through the Oil drain hose (see TM 9-2320-361-20, paragraph 3-18, page 3-29, item 3 and paragraph 3-19, page 3-30, item 2) I'll get a picture and see what they look like in real time (not a drawing).

Question to be answered: if the return line from the fuel nozzle is blocked by gack or whatever, and the fuel is pumping into that nozzle all the time (assumption, not sure how to prove it), the extra fuel has only one place to go and that's into the turbo. Just a WAG, don't know if it's even possible for fuel to get over to the turbo drain, which coincidentally(sp?)drains back into the crank case.

Now to find the camera and hope the batteries are still good.

 

[moving chicane]

Just had a thought. The only place where oil and fuel can come into contact with each other is in the turbo. Fuel is injected by the fuel nozzle (see TM 9-2320-361-20, paragraph 3-31, page 3-67, item 27). Oil is injected by the oil inlet tube and drains out through the Oil drain hose (see TM 9-2320-361-20, paragraph 3-18, page 3-29, item 3 and paragraph 3-19, page 3-30, item 2) I'll get a picture and see what they look like in real time (not a drawing).

Question to be answered: if the return line from the fuel nozzle is blocked by gack or whatever, and the fuel is pumping into that nozzle all the time (assumption, not sure how to prove it), the extra fuel has only one place to go and that's into the turbo. Just a WAG, don't know if it's even possible for fuel to get over to the turbo drain, which coincidentally(sp?)drains back into the crank case.

Now to find the camera and hope the batteries are still good.

I don't think this is right. If you were getting fuel in the turbo lube you would probably be getting oil in the compressor side of the turbo and it would be making an oily mess, not to mention decreasing the amount of oil in the crankcase. Also fuel in the turbo is generally not a good thing(needs citation).

 

[Heath_h49008]

There is no fuel in the turbo. Ever. (Unless we are talking unburned in the exhaust side)

 

[jeffhuey1n]

HH O rings, shut off rod O ring, or booster pump seal.

Each can be visually inspected for leakage with the in-tank pump running.

Doghead, seems like you've got the best of alot of good advice. Now to figure out where all these things are. I found the HH, removed and located 3 O rings. Two are large and I don't have replacements. I'll hold off on messing with them till I can find a source for them. The third is a small one, which I have a replacement for. i replaced it because 1. it was replaceable and 2. it was deformed...it weren't round any more if you look at it's cross section. I'll get it reinstalled as soon as the dang snow goes away for a couple days. The shut off rod O ring...that sound findable. Just follow the cable to it's end and start digging. The booster pump...not sure where that ones at. I know of the in tank pump, the manifold heater fuel pump and that's it. Is the booster pump in the IP? I'm going out on a limb here cause the book I've got (TM 9-2320-361-20) doesn't have the info I need, or I'm blind. 50-50 on that one. I have a hunch I need the correct book. Would you happen to know which one it is? I've looked through every TM I can find and aint finding the teardown on the fuel pump/HH/booster pump. Any assistance you could provide would be greatly appreciated. I used the search function which helped with the HH. Couldn't find a link for the other stuff, in a coherent form.
Jeff

 

[doghead]

Here's a picture from a TM of the Boost Pump. It is on the side of the IP and has a couple hoses connected to it. it is gear driven and the driven shaft has a seal that can leak fuel(into your oil).

The HH o rings and shut off rod o ring can be checked for leakage simply by turning on the ignition(powering the in tank pump). and with the shut-off cover removed, watch for fuel leakage.

Same with the boost pump, simply pull it out of the IP and turn on the in-tank pump, and look for leakage at the shaft seal.

There is a manual called "troubleshooting the LDS" that is very helpful for the fuel system.

There is also a TM just for the IP, TM 9-2910-226-34

 

[jeffhuey1n]

Thank you very much doghead! I drove my NCO's nuts as a young PFC and Lance Cpl because I couldn't find stuff in the TO. A simple bit of information is worth more than one of my infamous disertations. I get 60 degree weather again soon, Illl be testing o rings immidiately or as soon as the swamp dries out. Come to think of it, the cover (2 common aka straight tip screws held on a cover) is what sounds like the fuel stop cover. If it is, it was full of fuel when I pulled the cover. That is probably part of the problem.

Semper FI!
Jeff

 

[greg2560]

The o-ring on my shut off lever went bad and allowed diesel into the crankcase. Easy fix and one of the first places I would look.

That is what happened to mine!!! 2 gal over full!!!!

 

[phil2968]

Injection Pump Gasket Set For M35A2 and M54A2 Trucks, 5702663
Sounds like you need this.

 

[jeffhuey1n]

That is what happened to mine!!! 2 gal over full!!!!

That's what happened...twice. The second time AFTER changing the oil. At least I don't have to change the filters again, just drain them. Just ordered the gasket set, Thank you Phil for posting the information. It's finally warm enough today I might get to test the O Ring I changed out. I'm hoping...and a couple dozen prayers are on their way. Hope is there that he's not too busy.

 

[jeffhuey1n]

O ring on the shut off rod appears to be good to go. No leakage. Lot's learned on the HH and how to get it apart and back together again. Had to do comparitive maintenance on the shut off cable. I couldn't figure it out till I looked at another truck. I'll drain off the excess sometime over the next few days and see if it fixed the problem.

Leason learned...always push the shut off lever all the way in before removing the cover...