Fuel in oil, IP, LP?

[MMiller]

Last year my 93 pumped the crankcase full of fuel during the 1st gen meet. I looked at the IP and found fuel around the fuel pin and the aneriod spring. So I pulled the pump and resealed it. It then wouldn't run and made bad noises . I took it off and sent it to Bgilbert and everything that moved was broken inside the pump.....he helped me out and put enough core pumps together with what was left of my good parts and sent me back a pump to put on. It has ran pretty well since then, with the exception of start ups are smokey with blue smoke, and lately the truck smells like a diesel fuel leak. I've been checking the oil often and yesterday found it to be overfull again. I changed the oil last night and sure enough its fuel enriched again........

I have a low pressure piston lift pump that I put on several years ago. Can this style pump leak fuel into the crankcase? Can I pull it off and check it to verify if that could be my problem? I'm thinking I will probably have to pull the IP again, and send it to a local pump shop to run on thier test bench to see if the shaft seal is leaking, and having the injectors tested while I'm at it. They are a set of Bosch 185s that I've had for years, but likely only about 60,000 miles.

I cannot think of any where else the fuel can be getting in to delute my oil. Any suggestions?

FWIW Bill has already said he would take a look at the pump, no digs against Bill at all, him and I are good friends and there are no hard feelings. I'm just stumped at why I'm having this problem again.....after the NV5600 replace, and the truck being down all last summer with fuel system problems, I'm getting sick of working on the old girl. I just want it to run as reliably as it has the last 15 years.

Michael

[RCCUMMINS89]

The piston lift pump has an o ring that could leak fuel into the crankcase, but it would be a small amount.

How much fuel do you have in the oil?

[PToombs]

Michael, pull the LP and run your finger down the plunger. If it has fuel on it, then that's the problem. It should be easily noticeable, much easier than the diaphragm pump. I haven't seen one leak internally yet, and I've seen a lot of them. My bet is on the pump shaft seal again.

[bgilbert]

It has ran pretty well since then, with the exception of start ups are smokey with blue smoke, and lately the truck smells like a diesel fuel leak.

They are a set of Bosch 185s that I've had for years, but likely only about 60,000 miles.

I cannot think of any where else the fuel can be getting in to delute my oil. Any suggestions?

Michael, everyone else, wonder if one of the injectors needle valves are sticking open? Causing the blue smoke at startup, and over time, adding to the oil level in the crankcase? Some of the pump carnage could have made it's way to the injectors?

[RCCUMMINS89]

Good point, I over looked the blue smoke part.

[MMiller]

I changed the oil two days ago and checked it this morning. I traveled 130 miles pulling trailer and used an entire tank of fuel, and the liquid on the dipstick is nearly all fuel. Going to check fuel pressure tomorrow before pulling the system apart...just what I needed.

[MMiller]

Since I'm on the computer now I will type a better response. I have a large amount of fuel in the crankcase. I'm not so sure an injector could dump that much fuel in a short time or not. Like I said before, I will check fuel pressure to make sure I'm not making too much pressure, then I will start to disassemble the system. This time I will pull the lift pump and inspect, and if thats not the culpret then the injection pump and injectors are coming out.

After I changed the oil and nothing else, upon startup there was no blue smoke or missing. That problem seems to be hit or miss. Sometimes it will fill the garage with blue smoke on startup and miss for 10 minutes, and sometimes it will start and idle almost like normal. I just hope I haven't hurt anything yet. The engine doesn't seem to rattle, but I wonder how the turbo bearing has taken mostly fuel, especially since I was running alot of 20-35 psi of boost hauling hay yesterday. Going to check the turbo bearings too I guess.

Thanks for all the advice guys. I hope to have at least one of my first gens back to running when you show up in June.......

Michael

[Mark Nixon]

Are you sure the diaphragm on the lift pump didn't rupture?

I had a HPPLP that I'd installed on a VE engine leak fuel to the oil on me a few years ago.
When I swapped in an electric one, the problem went away.
People said I was crazy then, that the HPPLP had pushed out the seal on the VE, yet the fuel in oil issue went away with the electric pump.

That was before I knew the HPPLP/LPPLP weren't diaphragm pumps and that running a HPPLP with a VE could be disastrous.
To my knowledge, it never DID push the seal out, though.

Mark.

[RCCUMMINS89]

Even though there isn't the diaphragm that can rupture.... they do of course have an o ring on the rod that is operated by the cam lobe. It would be nowhere near like a regular diaphragm rupture but it could leak some into the crankcase. I'd be hard pressed to think that much though in 130 miles. that's like 20 gallons WOW

[Mark Nixon]

When the one went in my truck, apparently it went right before I filled up.
After I filled up I noticed the the fuel level was moving off the full pretty fast and the oil pressure started going really erratic.
When I pulled over to figure out WTF was up, the trailer and whole underside of the truck was hosed down with diesel fuel/engine oil and still dripping.

Near as I can figure in the space of 30 miles it went from good to go, to total failure of the lift pump into the crank case.

This is the biggest reason I prefer electric pumps, at least they won't destroy the engine by leaking fuel into it.

Mark.

[RCCUMMINS89]

Well.... that is the first I've ever heard of a piston lift pump pushing fuel into the crankcase..... from a 1st gen or a 2nd gen truck. Learn something new every day.

[MMiller]

Today I put a fuel pressure gauge on the filter base. At idle to 2500 rpms I had a rock solid 12 psi of fuel pressure. I did not check it under load because I have so much fuel in the oil pan. This afternoon I started pulling the front clip off to pull the injection pump......and you may wonder why? I figured I'm pulling the injection pump, injectors and the front cover is leaking oil so it needs to be fixed, I just as well fix the cowl cracks while I am at it. So likely when you guys are here in a couple weeks, you will see Old Red in a state of dissassembly.

I plan on pulling the injection pump and hooking up an electric fuel pump and put 12 psi to it and then see if fuel comes out the front seal.

Michael

[PToombs]

It may not leak if it isn't turning.

[MMiller]

It may not leak if it isn't turning.

Yes, but I will wiggle and turn the shaft. Our local pump shop is wondering if the bushing needs to be replaced in the front of the pump, if its allowing the shaft to move up and down the lip seal can't keep it sealed.

Michael

[m880cummins]

I helped a guy the other week replace the IP seal. He has a rebuilt motor in his 660k truck and it had about 400 miles on it and he called me saying it was pissing diesel out the crank case vent. Needless to say, the seal was messed up. He had 3 gallons of diesel in his crankcase Looking at the seal, the lip was pushed out. Apparently the pump was just rebuilt so it could have been a poor quality seal, improper installation or maybe, just maybe, the wrong lift pump. It had a piston lift pump but I didn't check the fuel pressure. It may have a p pump piston lift pump in it which would be bad. He said he hasn't seen any issues since we did the seal though.

Doing the seal only takes about 2-3 hours. You don't need to pull the timing case cover but if you have leaks and a unknown dowel pin status, you might as well get it all done.

Charlie