The fuel could be simple fix more than likely a hose or loose clamp or fitting.
The rear main keep an eye on the oil. Unless it pouring out drive it till you have a a reason to drop the tranny. Put a drip pan under if your worried about oil on the driveway

 

Yeah...it's a bit more than a minor leak Though it only seems to be leaking while the motor is actually running. This is just from the few minutes of running it at 2000 RPM while checking the timing.

It's been dark spotting the property for some time, and I assumed it was oil, but I think it's actually the fuel dripping that's causing the spotting.

 

Get some brake clean and clean the oil of the engine from the spots and location it looks like oil but it to far to the left for resr main. Look at oilpan and valve cover. Check where the oil return from the turbo goes into the valley pan.

Even after you change the oil it going to turn black

 

Did you have the air filter off? No doubt a rear main leak, mine was horrible as well. Usually the air filter forces the crankcase to pull vacuum via the cdr. If you had no air filter, no vacuum to keep oil from going past the seals.

 

Running a Banks K&N style filter. Though I did notice black oil in the air side of the turbo, and in the intake, last time I had it apart to replace the throttle cable about a month ago. It literally just occurred to me, and by that I mean about 20 seconds ago , that it's probably long past the time that valve should have been inspected/cleaned/possibly replaced along with the drain hose.

I know oil collection in the intake is a sign of CDR valve service time (and why it didn't occur to me last I had it apart is a mystery)...but could a dirty/failed CDR also cause seal leakage like this?

 

Actually, oil in the intake is just part of the CDR doing its thing. It vents crank case gas to the intake, youre going to have some oil condensation on things as a result. Was a guess, wondering if you had the filter off. Mine would drip after i shut it off, but never leaked going down the road. Until my dad had it serviced at some quick lube outfit, they didnt hook the cdr tube up right, which kinda blocked it. In 90 miles is spewed out about 10qts of oil via valve covers, oil pan, and main seals. Just drenched the bottom of the pickup.

 

The CDR is generally "open"; it just prevents the engine from pulling a vacuum against the crankcase if the air filter gets really clogged(which could cause a runaway, too)

 

Mine was spotting the ground where ever I parked it, and I have to add oil to it occasionally, so I just assumed that the spots on the ground were oil drips. It also was dripping a bit while my buddy and I were servicing the AC system, but it wasn't anything major. I did recently replace the lift pump with another mechanical, so it's entirely possible that I just didn't get the hose clamp on tight enough, or the hose was damaged when pulling it off the old pump/putting it on the new pump. I'll get under it this weekend and replace all of the rubber down there with new.

That major spray/puddling was after running it at 2,000 rpm while checking the timing. I never really noticed anything oil wise while running down the road, but then I'm not sure how I would even check that, lol. Given that it got much more major at higher RPM, that's why I thought maybe the CDR was involved, and wondered if it WASN'T working properly/hooked up correctly, if it could cause this oil spray issue.

From what I've been reading on it, it sounded like the CDR was also there to vent excess crankcase pressure from blow by, and that's why it needs to be cleaned and/or replaced occasionally? If it isn't doing it's job, it allows crankcase pressure to build, which would explain why the motor is spewing oil at higher RPM. Or am I way off track on this?

 

If it fails it fail to the open side not like a gasser PCV valve that fails to closed

 

Do you have a pressure washer? If so, My recommendation would be to climb under the truck and clean up all crud areas. Then search for the leak. Might make it easier to tell if it's fuel or oil or something else.

Glad to hear adjusting the timing had a positive effect. As far as mileage #'s, you should be getting better. Along with your injectors, do all the easy stuff like checking for dragging breaks, greasing the wheel bearings etc etc.