Rear crankshaft seal

I believe the rear crankshaft seal on my B5.5 needs replaced.

When I dropped the splash guard in order to change the oil, I noticed a fair amount of oil on the rear of the splash guard. Basically, oil was splattered over the sway bar/cross member. So, I took a look underneath the motor, and it was pretty much covered in engine oil.

The leak looks very similar to image 6 on the following link at BlauParts: http://www.blauparts.com/vw/vw_oil_leaks/vw_passat_oil_leaks.shtml

What would cause the rear crankshaft seal to leak? Possibly a blocked crankshaft ventilation tube? How do I prevent this from occurring again?

How difficult is it to replace the seal?

For reference, the car has 158,600 miles.

Thanks very much in advance for the help,

Andrew

I would clean the area off really well and make sure where it is coming from if you haven't already done so.

The seal is easy to change after you drop the trans. It's not that bad if you have converted it over to a manual trans. If you still have the automatic you have to drop the subframe. Not that hard, just takes more time and it is very heavy. An ATV jack makes it a lot easier to pull.

Thanks Jake Brake.

I cleaned the area as best I could yesterday, cleaning/drying off the juncture of the motor and transmission. I am guessing that maybe I can drive it around a bit, then get back underneath to see if, in fact, this is what is causing the leak.

BlauParts seems to suggest that a blocked CCV tube could be the culprit. Is there a way to check the CCV or other area to see if it is clogged? I searched the B5.5 forum for CCV, but didn't find any threads that seemed to point me in this direction.

I very much appreciate the help.

Check the back of the motor from the top. Could be either the valve cover running down, or the tandem pump gasket. Mine is leaking a bit from the back corner of the valve cover and runs all the way down.

the tandem pump can really slime things up. I'm waiting on one now. I changed out my tandem pump gasket, but it appears the pump is seeping oil and a little diesel.

Uberhare and Jake Brake,

Again, thanks again for the replies. I believe I really jumped to a conclusion in my first post.

I took a look at the valve cover and I think it may be leaking, as there is oil sludge along the edge which gets progressively worse when getting to the rear corner (rear corner being the passenger side). I can see oil that appears to be seeping down from the top of the head gasket. I am not familiar with the tandem pump gasket, but I am guessing it may be leaking, too.

I am guessing the safe bet may be to replace the valve cover gasket along with the tandem pump gasket.

Thanks so much for the guidance, and I will let you know what I find out.

I searched the forum on valve cover gasket and tandem pump gasket and found a great thread (one of many): https://forums.tdiclub.com/showthread.php?t=336418

The thread basically suggests replacing the following:
Valve cover gasket PN 038103483D
Tandem pump gasket PN 038145215
Coolant flange PN 038121132D
Coolant flange o-ring (I believe this is included with the coolant flange - I don't know the PN for just the o-ring)
Coolant sensor PN 059919501A
CTS retaining clip (I don't know the part number)

Again, thank you. And I will let you know what I find out.