I have a '01 Discovery II. I have been chasing an oil leak for a couple weeks now, following similar issues I have found on other threads, but I am out of ideas and I need help!!! Origionally I was driving down the highway and a cloud of smoke was following me. Oil leak seemingly from RH valve cover was dripping on exhaust and CAT causing the issue. Replaced Valve cover gasket and it seemed problem was fixed, no issues with around town driving. Got back on highway this morning and it was back! Looked like valve cover gasket again, but saw some bubbles and realized I had positive crank case pressure. Pulled oil separator "baffle" and it was packed full! Cleaned it out drove around at high RPM around industrial park and no issues. Got on highway on the way home and low and behold, I cant see the car behind me it's smoking (oil dripping on exhaust). Seems to be dripping out of "J" vent tube behind right valve cover gasket. What does this do? What is going on? Need help!!!

 

The inverted J tubes vent things like axles, tranny, transfer case. So check each of them for fluid fill level. The PCV system has two sides, it vents both valve covers. The driver's side (NAS) goes into the throttle body, and when you pull it out and clean it also clean the bore it goes into. Mine was ooey gooey.

 

Ah man don't worry at all.
Savannah tagged and bagged this one for you.

Those "J" tubes are oil vent tubes.
They vent the oil in the transmission and I am guessing other things filled with gear lube.

Trick with them - keep them up high.
That is where they go.
Yours got untied from the firewall.

If they get down low, they leak - on to the cats, the o2 sensors and all that.
and, they finally lay on those items and melt into nothing.

So, heed this call.
Do get those tied up as high as possible and keep a watch on them.

As soon as you tie them up = no more oil.

Good catch on the positive crank case ventilation issue.
That was also a huge win for you.

 

So, if you are venting from 1 of the 3 vent tubes, better figure out which is loosing fluid then check and refill that unit so you don't have a bigger problem from low fluid levels.

 

BTW, those "inverted J" tubes are supposed to be high and out of the way of water should you find it required to go "wading".