Rear main seal? Or not.

[ramblemutt]

'01 Excursion. Oil dripping out underneath all of a sudden and I'm leaving a trail of oil. I've shut her down. My first suspect would be rear main seal, but only 80K miles on my Ex. Somebody said that usually when this much oil loss generated, it's coming from some kind of plug thats' up above the rear of the engine and not the rear main. Anyone know what this plug is? I've not much experience with this. Any ideas?

[nahger1011]

turbo orings or High pressure oil pump orings. rear mains rarely go out on these trucks. o rings on the other hand are very common. Check out powerstrokehelp.com. Lots of good info

[SuperCrutyPS]

Get up on top and check the valley. There is a weep hole in the back that if oil is in there, it can leak out, run down the block/bell housing and drip on the ground. If there is oil up there, then you'll need to figure out where it's coming from. If there isn't, it might be the RMS, but many people say not likely. Another place to look is crawl under and look up the sides of the block. Maybe valve cover gaskets?

Another question - Are you sure it's oil and not tranny fluid? My '01 popped a seal on the front of the tranny and was dripping a LOT. Trans shop said it's common on the 4R100s.

[mastertech11]

check the turbo pedestal mounting bracket. it has o rings for oil drain and feed, also its common for the exhaust back pressure actuator to leak. you can see it with a mirror or looking up from the bottom of the transmission, its a cast alum. bracket with a large round oil passage and has a cap with a snap ring, it may be leaking at the rear housing at the shap ring location.

[jesilvas]

There is a sticky:
Hpop o-ring video
99-03 7.3 oil leak diagnosis
Oil Cooler

[jaysonmore]

I found this site very informative in helping me find this hpop leak but educate me on the powerstroke so I can work on it and save myself some $.
POWERSTROKEHELP.COM - The Information Source for Ford Power Stroke Diesel Owners

Simple o ring fix from Grainger for $4 for 25 o-rings.
Or use DieselORings.com which is 1/2 $ of Ford.

Replacement O-rings for Ford Diesel Engines

[ramblemutt]

Update on oil leak. My mech (of many years) says there was a breach in the rear of the oil pan. He repaired the breach with a weld job and is testing as I type. He says it appears to be a stress breach of some kind. I've never heard of such a thing.
Any experience out there with something like this?