MDdeuce
Member
- 58
- 35
- 18
- Location
- Whiteford MD
Alright guys, I seem to have small amounts of fuel in my oil. I hate to start another thread about this, but I have read the majority of the others and am still a little confused. I also read through the IP TM (TM9-2910-226-34).
Here is what happened:
-Did an oil change (first one under my ownership), drained out a little over 5gal of oil. Looked and smelled like oil.
-Sent oil off for analysis, came back that it was 7% diesel fuel – not good.
-Researched on SS and read the TM.
It is my understanding that there are 13 places that fuel can contaminate the oil:
1) FDC
2) fuel shutoff actuator o-ring
3) HH o-rings (2 of them)
4) boost fuel pump seal
5) flame heater (if equipped)
6) fuel injectors (6 of them)
7) plunger in the HH
Above seems to be in order of likelihood. So, some immediate eliminations, no flame heater, truck purrs like a lion, so unlikely it would be the plunger or fuel injectors. Did some additional testing:
-Took off the fuel stop cover, engaged the lift pump (electric tank pump), and watched. There was no apparent drops or leaking of fuel from the HH o-rings or fuel actuator o-ring. I left the lift pump on for several minutes.
-Removed the FDC (mine is not bypassed), engaged the lift pump, and watched. There was no apparent drops or leaking of fuel from the friction fit seal at the top of the limiter arm. I left the lift pump on for several minutes.
-Unbolted boost pump and slid it out to the steering gearbox, ran the lift pump and watched. A little bit of oily liquid oozed out, but no signs of fuel running down the shaft of the pump to where I could see. Again left the pump on for several minutes.
Nothing seems to be leaking, and it sounds like from the posts and few videos folks put up that these seals should be obviously leaking with the 10psi from the lift pump behind it.
Confused, some thoughts I had:
I did not have much fuel in my oil, only ~1qt, so I caught this early. Could it be that some seal is just starting to fail at the higher pressures of the boost pump or the HH and I just will not see it with the tank pump pressure?
My truck can be a little hard to start sometimes, so I’m wondering if my tank pump is getting tired and not actually getting fuel behind those seals during my test. Should I run the truck briefly, then stop it and leave the tank pump on, and re-test so I know fuel is there?
My truck also smokes a lot when cranking and first starting. Could I have a leaky injector that is ever so slowly leaking a little bit of fuel into the piston and past the rings every time the truck is parked? If so, how do I tell which injector?
How much oil pressure does the IP see? Could I leave the fuel stop cover or FDC off and inspect it with the truck running so there would be 60psi from the boost pump behind these seals? Or will I get everything covered in oil and not get proper pressure/lubrication to the rest of the engine? I have a feeling that this is not really a good idea.
Should I just wait and closely monitor oil levels and see if the truck starts to make oil at a noticeable rate? I have no idea how long the old oil was in the truck (but I’m guessing 5yrs+ from former owners comments), it might have taken years to build up this much fuel.
Or should I just break down and replace all the IP seals and bypass the FDC? Probably will make me sleep the best at night. I don’t have a pryometer to adjust the IP fuel flow, so I would prefer to not bypass the FDC just yet, and getting the boost pump out seems to be an ordeal.
Any thoughts, comments and recommendations from experience would be appreciated. I’m registered for a 4th of July parade, so need to figure this out soon or there will be truck load of disappointed kids.
Here is what happened:
-Did an oil change (first one under my ownership), drained out a little over 5gal of oil. Looked and smelled like oil.
-Sent oil off for analysis, came back that it was 7% diesel fuel – not good.
-Researched on SS and read the TM.
It is my understanding that there are 13 places that fuel can contaminate the oil:
1) FDC
2) fuel shutoff actuator o-ring
3) HH o-rings (2 of them)
4) boost fuel pump seal
5) flame heater (if equipped)
6) fuel injectors (6 of them)
7) plunger in the HH
Above seems to be in order of likelihood. So, some immediate eliminations, no flame heater, truck purrs like a lion, so unlikely it would be the plunger or fuel injectors. Did some additional testing:
-Took off the fuel stop cover, engaged the lift pump (electric tank pump), and watched. There was no apparent drops or leaking of fuel from the HH o-rings or fuel actuator o-ring. I left the lift pump on for several minutes.
-Removed the FDC (mine is not bypassed), engaged the lift pump, and watched. There was no apparent drops or leaking of fuel from the friction fit seal at the top of the limiter arm. I left the lift pump on for several minutes.
-Unbolted boost pump and slid it out to the steering gearbox, ran the lift pump and watched. A little bit of oily liquid oozed out, but no signs of fuel running down the shaft of the pump to where I could see. Again left the pump on for several minutes.
Nothing seems to be leaking, and it sounds like from the posts and few videos folks put up that these seals should be obviously leaking with the 10psi from the lift pump behind it.
Confused, some thoughts I had:
I did not have much fuel in my oil, only ~1qt, so I caught this early. Could it be that some seal is just starting to fail at the higher pressures of the boost pump or the HH and I just will not see it with the tank pump pressure?
My truck can be a little hard to start sometimes, so I’m wondering if my tank pump is getting tired and not actually getting fuel behind those seals during my test. Should I run the truck briefly, then stop it and leave the tank pump on, and re-test so I know fuel is there?
My truck also smokes a lot when cranking and first starting. Could I have a leaky injector that is ever so slowly leaking a little bit of fuel into the piston and past the rings every time the truck is parked? If so, how do I tell which injector?
How much oil pressure does the IP see? Could I leave the fuel stop cover or FDC off and inspect it with the truck running so there would be 60psi from the boost pump behind these seals? Or will I get everything covered in oil and not get proper pressure/lubrication to the rest of the engine? I have a feeling that this is not really a good idea.
Should I just wait and closely monitor oil levels and see if the truck starts to make oil at a noticeable rate? I have no idea how long the old oil was in the truck (but I’m guessing 5yrs+ from former owners comments), it might have taken years to build up this much fuel.
Or should I just break down and replace all the IP seals and bypass the FDC? Probably will make me sleep the best at night. I don’t have a pryometer to adjust the IP fuel flow, so I would prefer to not bypass the FDC just yet, and getting the boost pump out seems to be an ordeal.
Any thoughts, comments and recommendations from experience would be appreciated. I’m registered for a 4th of July parade, so need to figure this out soon or there will be truck load of disappointed kids.
