I'm new to the forum and just bought a 6100D from my neighbor who was the original owner. It has just over 2000 hours on it. It runs well and starts easy. He is a former mech. who took good care of it. Very recently he discovered a little diesel showing up in the oil. He has been shutting off the fuel petcock when shutting it down. The WSM I have for it talks of either defective nozzle(s) or a fuel pump plunger leak. I'm just wondering how a guy can tell which of these needs to be fixed. I know I could just replace everything but I was wondering if there are any ways to tell what the problem part is?
6100d fuel in oil
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North Idaho Wolfman
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If it's starting and running really well like you say you can rule out the 2 things you just said it could be. Bad injectors would cause it to run poorly or have a real hard time starting. Bad lift pump and it will normally cut out and stall at higher RPM's. Most likely cause of fuel in the oil is from a bad injector pump.
I found out that the injectors where all checked out by a local diesel shop and are good to go. The fuel pump plunger idea I had was something I read in the troubleshooting section of the Work Shop Manual. The injector pump is something I hadn't thought of and I'm going to have to read up on. I guess my next question is, how safe is it to keep using it and just shut off the fuel after use? Changing the oil more frequently to boot. The previous owner hasn't had any more trouble with fuel in the oil since he started doing that.
North Idaho Wolfman
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
It might be worth pulling the lift pump and checking it, if it is leaking it's a cheap fix.
Sounds odd that he can keep the fuel out of the oil just by shutting it off when not in use?
The injection pump would put fuel in the oil while it was running but unlikely that it would leak much when it was not in use.
Sounds odd that he can keep the fuel out of the oil just by shutting it off when not in use?
The injection pump would put fuel in the oil while it was running but unlikely that it would leak much when it was not in use.
Since the relift pump is gravity fed it dont have much pressure on it, but if the diaphragm
is cracked the fuel between it and and injector pump would drain back down through the crack into the engine. When you shut off the engine, two of the injectors are still loaded with pressure. If one of the injectors leaked down you could get fuel that way also the pump has internal seals that can leak by into the engine. I am like Idaho wolfman if either of these was wrong it would seem like it would run rough except for the leaking injector pump.
is cracked the fuel between it and and injector pump would drain back down through the crack into the engine. When you shut off the engine, two of the injectors are still loaded with pressure. If one of the injectors leaked down you could get fuel that way also the pump has internal seals that can leak by into the engine. I am like Idaho wolfman if either of these was wrong it would seem like it would run rough except for the leaking injector pump.