Homestead

I am totally stumped on this one and could use some input. Explanation is a bit long.

Truck is as my sig says. This morning like every morning, backed the truck out of a fully insulated but not heated shop, let it idle for about 10 minutes to warm up and then headed to work. Weather was the usual -30 plus weather for our area.

I drove the truck about 20 miles or so eventually getting to 60 mph after she fully warmed up. As I was downshifting to come to a stop for a intersection, I happened to glance at the gauges and saw the oil pressure heading for zero in a real hurry. I shut it off and coasted to the side and stopped.

I got out and smelled oil, lot's of oil! All down the sides, underneath, everywhere. Checked the dipstick and it was dry. Actually knocked on the oil pan and it was hollow, nothing in there for sure. Called for a flat bed for a haul home.

Tow truck dropped it off in the driveway, I got underneath and pulled the drain plug, got maybe 3/4 of a quart and then drips.

I looked everywhere to see where it came from but because of the volume of oil everywhere it was for the most part impossible. I went and got the pressure washer and was going to clean as much of it off as I could to see if there was anything to give me a clue. In the meantime, I put the heat on in the shop.

I couldn't find anywhere that it could have pumped the oil from so I figured, Let's fill it up again and see if it will fire up. If the bearings are wiped out, then I will know also. Truck fired up and sat there at idle and no leaks, drips, booms or nothing. Oil pressure is where it should be and it acted like nothing had happened at all. Scratched the old noggin at that point!!!

Took it for a drive and she went as usual, nothing out of the ordinary other than one eye glued to the oil pressure gauge. About 15 minutes into the drive, oil pressure plummets to zero and I shut it off coasting to the side of the road. Get out and same thing, oil everywhere and the dipstick is dry.

Second tow home and we roll it into the shop. The heats on so it's a little more comfortable other than the oil dripping everywhere. After about 10 minutes of laying under the truck looking for whatever I'm looking for I hear a tinkle, the sound that an icicle makes when it hits the ground.

BINGO!!!! Years ago I got rid of the puke bottle and routed a new hose down the side of the motor so it hung right beside the front diff as my new road draft breather. It froze up and plugged, about a 9 inch icicle 3/4 inch around, the perfect plug for a 3/4 hose.

So now I know the breather plugged. The truck has 350,000 km's on it and has some blow by as well as the vacuum pump leaks so it's adding it's little bit to the pressure inside the motor. With a plugged vent, it has to go somewhere.

That's my question, any ideas where the oil came from?

It's mainly towards the front and all down the passenger side of the motor, driver side is basically dry. The fan of course picked some up and blew it everywhere as well as the entire underside is now rust protected by 24 quarts of synthetic Rotella.

This afternoon, after I cleaned everything I could and looking everywhere I could imagine I filled the truck again and went for a drive, ending up almost 200 miles worth of driving!! The truck never missed a beat, never puked a drop of oil and runs as good as it did the day before.

I know a dodged a serious bullet, twice, but I cannot find where this oil puked out from. The front seal doesn't leak, the front cover doesn't leak, Oil filter is still tight and no drips, the valve cover gasket doesn't appear to have blown out, NOTHING!

Any ideas???

Sorry again for the long explanation but I wanted to be as detailed as I could.

Jeff

Purplezr2

Turbo Return to the Pan?

Busboy

Could have split the puke hose up stream from where it froze and with no pressure you can't see it?

ghenges

"Turbo Return to the Pan?", Purplezr2's response, makes the most sense. The pressure build up in the crankcase (really the whole engine inside) relieved itself by separating the weakest point of the gasketing or external attachments to the crankcase.

Being the passenger side front seems the most oily, check the integrity of the turbo oil return plumbing.
The return line slip fits into the block. The fitting is relatively easy to remove and mostly can be removed just by pulling on it, so it is possible the fitting could have been been blown out off the hole, it may now just be sitting atop the hole.

There is also an extra hole in the block towards the back the is sealed with a cup plug, it shouldn't have blown out but check it just the same.

My theory is that the turbo return line fitting at the block blew out (or the rubber hose just above it split or separated) permitting the turbo return oil to escape because the pressure coming from the crankcase was blowing in the opposite direction stopping the oil from entering the block.
The turbo return oil, which normally would be unpressurized, could possibly have been pressurized to the pressure within the crankcase resulting in a faster escape than just dripping out of the return tube.

Further the theory postulates that oil escaping from the front seal, the front cover gasket or the valve cover gasket would have escaped at a slower rate than the oil being supplied to the turbo which is under pressure on the top side of the turbo.

One method of finding out for sure just where the leak occurred is to CAREFULLY pressurize the crankcase through the breather tube with 2 or 3 psi of air pressure.
Keep the air pressure connection to the breather tube as loose as possible to contain the 2-3 psi so it will blow off in the event pressure would get too high.

You must find where it leaked to make sure dirt and water can't enter the engine where ever the crankcase pressure found its way to the outside of the block.

Lil Dog

Even if the seals don't leak under normal conditions, a few inches of water pressure in the crankcase can make them puke hard. The turbo return line sounds logical as well as its one of the few places thats just a hose and some clamps.

Geeze, good job you trust your gauges and stopped!

Homestead

I have checked everything that has been mentioned and I am stumped.

In fact, about 5 minutes after I posted this, I got in the truck and did another 2 hour round trip and nothing, no drips, no leaks, zip.

The turbo drain back was one of my first thoughts but everything is tight and I can't find a split hose at least visually. For what it's worth I'll just replace it and rule it out altogether.

I'm actually surprised there wasn't a fire or at least smoke with the way the engine compartment was oiled down but again, it was mostly to the lower side of the manifold.

The thing that makes me wonder is that it emptied the pan almost immediately. Is the turbo return just a dump into the pan? That being the case, pressure will follow the path of least resistance and it may very well be the return hose.

I'm going to drive it, carefully, for the next day or so and then I get to put it back into the shop for the dreaded heater core change. While it's down I'm going to pressurize the motor and see what goes POOF!

My thoughts are a gasket blew out or a hose split. I don't think it's a mechanical item like a block plug or something along that line because it would leaked something already with the hours of driving after the incident.

The good thing about all this is I dodged a bullet and didn't lose the motor and got one awesome corrosion treatment on the undercarriage!!

Jeff

nickg

I would not sweat looking for where it came from, knowing you found the plugged vent is enough.
The military HLVW's have a PVC system that vents to atmosphere, it has a valve inside that will freeze up in really cold weather, and that 6cyl will puke oil out of just about every seal... just removing the PVC, and washing it out and re-installing it, cures the problem, and I have never seen any ill effects, like seals starting to leak after the fact

ghenges

Question:
What was the evidence that the pan was emptied almost immediately?
Did you stop and check the oil level periodically on your test trip?


Regardless of nickg's advice to ignore finding the source of the leak, finding the source seems a prudent course of action since it's your own vehicle and the military won't be paying your future repair bills. Ignoring it will be relying on luck to some extent..I am never that lucky.

From your description the oil didn't escape from every possible likely expected place, but was confined to one general area (the passenger side).

It's not difficult to ascertain the area where the leak occurred.

The peace of mind alone is worth the 20 minutes or so it would take to pressurize the crankcase to determine with certainty the source of the spillage.

Tate

My bet would be on the hose on the drain is split and opened up once pressurized and dumped oil out. I know when my turbo drain loosened off on my primary turbo, it made a hell of a mess all underneath, and it only dropped 1/3 litre over 200km. You'll have more oil flow through a journal bearing turbo than a ball bearing.

rebal

BY the off chance did you check your fuel tank and see if it pushed it through an injector Oring and in to the return line? I know its all over the bottom but may be some went there or it pushed it out a gasket onder the pressure when the blow by tube was pluged

SIXSLUG

You might consider cutting the end of your puke hose at a steep angle to provide a slightly larger escape area that will be harder to plug up.

Just a thought...

dozer12216

First choice is turbo return hose.
Second is tappet cover but it on driver side.
third is breather setup or breather assy cracked.
fouth is front cover leaks up high.
5. Is vacuum pump or seals but on wrong side.
Last might be head gasket.
A prudent person would clean and drive for a few minutes and check for oil. Talcum powder dusted on dry engine will point to leak if don't drive till pumped 2 gallons of oil all over the place. DUH!

rattlerbob5.9

Why not try something very simple = recreate the same problem that originally caused it to dump the oil.

By this i mean with the truck running pinch off or restrict the vent hose and then check for cracked hoses or other leaks as mentioned.

I would do this outside of your shop not out on the road, and if you can have another person in the truck speed up the rpm if needed as well as to be able to turn it off quickly.

Homestead

Found the leak.

I washed the entire engine compartment last night as well as underneath and everywhere else I could see. Everything was spotless. Oil was topped up, filter tight, etc, etc.

Did my usual routine starting, warming up and away we go. 3hours straight driving as normal. Pulled over for coffee and took a look under the hood.

It's drooling in the upper left of the front cover, obviously pushed a chunk of gasket out. Hard to see with the alternator and water pump in there but it's drooling. Drain from turbo is as dry as a bone as well as everything else mentioned. Drove another hour to my destination. Before coming back, washed the wet spot and headed home. Arrived here this afternoon and it's drooling in the same spot. It's a new leak, never been there before. Nothing serious at all but enough to drool. I guess with pressure behind it from a plugged vent, it's a big leak

During the trip, my mileage was as usual, no smoke, noises or burps, never noticed anything out of the ordinary, truck just ran as it always does.

I'm just surprised that it barfed the entire contents of the pan. It was full on the dipstick because I fueled and checked the oil 8 hours previous to the original incident. After fueling, the truck was driven home 5 miles and parked. When it was towed home and I pulled the drain plug, maybe 3/4 of a quart or so. There was zero warning other than seeing the oil pressure gauge plummet.

So it's front cover and seal time. Might make it a double header this weekend and take on the heater core at the same time.

Appreciate the input guys as to where to possibly look.

Jeff

Scotty

Just saw this thread. Thats exactly what my 01 did. I cleaned it up the first time and nothing happened on a run to the city and back. Next day, fired it up and never made it out of the garage...puke. Fixed leaks. Cleaned again...puked...next weakest link...head gasket. O-ringed the head.


Watch closely for new leaks after you repair.