'01 PSD motor oil into fuel tank

orange150

orange150

Well-Known Member
Joined
Mar 20, 2005
Location
Fairfax City, VA
my brother in laws '01 PSD has been running pretty terrible for a while and today while working on it he said he figured out that all his oil was being pumped into the fuel tank. He told me that he put 2 gal. of oil into the crank, drove a little ways down the road and when he came back he pulled the fuel filter and it was full of oil and that oil was dripping out of the fuel pump.
The truck had been in and out of at least two shops, the first shop replaced glow plugs and i think even some injectors and the last shop said that the #8 cylinder might be bad. any one heard of this before?
Thanks!
 
Does he check the oil level to confirm this? I don't see how it could pump motor oil into the fuel system, but I don't know 100% that it couldn't happen.

Diesel fuel is oil, so even if it is pumping motor oil into his tank it should still run fine (I run oil in my 99' mixed w/ diesel and it runs fine). I'd check to see if the fuel is bad, maybe drain the tank and flush the system. I've seen black diesel fuel before, and don't think I'd want to run it in my truck....
 
yea i don't see how that could happen either, he just told me on the phone, i haven't seen it yet. and yes he did check the oil, when it was running somewhat decent he had to add a few quarts a day.
 
I'm with everyone else here, i don't see how it could be in the return to the tank.
The fuel system return is on the fuel bowl before the engine. Factory fuel deadhead in the engine.
The only theory I can think of is the oring(on the injector) between the High Pressure Oil system and fuel system is bad or missing so maybe the 500-3000psi oil is reverse pressurizing the fuel (50-60 psi) system, but I don't even know if its possible.
 
Im more familiar with the 6.0 diesels, but I believe there was an injector issue with the 7.3 diesels allowing oil into the fuel system. If im not mistaken there is just one o-ring on the 7.3 injector separating the high pressure oil system (which activates the injector) from the fuel supply system. If that o-ring were bad or the injector cracked near it, that could explain your problem. The 6.0 injectors were supposed to be redesigned to stop that issue, but they had their own problems:shaking:.

Hopefully someone with 7.3 experience will step up, or you could try searching on www.thedieselstop.com (a ford diesel specific site), or www.thedieselgarage.com (a general info diesel site). Both sites have a large amount of info and a huge knowledge base.
 
Just in case some of you may be curious (which is probably not many), here is a response I got over on thedieselstop.com
I would bet you money that who ever replaced those injector Orings nicked one or more of those Orings and they need replaced again... No quicker way to fill the fuel system full of oil than with a missing or damaged injector oring!
#8 cylinder might be bad? Maybe, but it might just be a way of this shop of getting out of some warranty work when they screwed up when re-installing those new injectors. Have you BIL ask what or why leads them to believe that #8 is bad. Only one way to determine that, and its through a compression test, and NOT from a cylinder contribution test done a scanner (computer)!!!
Last but certainly not least. I would very much like to hear HOW a bad/dropped #8 cylinder could possibly pump oil into the fuel system? NOT gonna happen! It would definitely make the engine run rough, blow white, grayish or even blue smoke, butr its just not gonna feed oil to the fuel system. All of the above could definitely happen with bad injector orings. Don't let some cheesy shop charge your BIL $8K for a new motor when all it needs is $20 worth of new orings!
Click to expand...
 
I figured someone at one of those sites could point you in the right direction. They have certainly helped me out a few times. :)
 
I work on quite a few fleet PSD's have your brother bring it to me i won't hurt him . I have made some special service tools that allow me to pressurize the heads with 3500psi this allows you to pull the valve covers and see if there are leaks. also if the heads don't hold oil pressure then theres is a leak. Of course this has to be done with the vehicle not running. Hence the tool. The fleet vehicles i have worked on, our ran hard and not cared for well, they come in in very rough shape so i have been forced to learn more than i care to know about a seemingly great motor.
 
whoa Cperry just saw that reply! I will tell him about that tomorrow when I see him. Only thing is it will need a pull down there and we don't have a trailer big enough to accept a 4 door long bed truck. I'll PM you if anything comes of it. Thanks again!
 
mike, it'll go on my trailer just fine if you want to borrow it sometime. or, i can pull it too, whatever.
 
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