The Oil Filter Housing Assembly/Heat Exchanger, Oil Filler Tube area and Alternator Seal are the usual suspects oil would be coming from. Fuel & Tandem pumps leaking are not going to throw oil into the valley.

You can either source all the seals/gaskets for the oil filter housing/heat exchanger, or you can order a whole new assembly from VW (if available) I've gone both routes before, and they both have pros and cons. It's not hard to replace all the seals/gaskets on the heat exchanger, but it's tedious to find all the P/N's you are going to need. If you get a new one, it's already assembled, and you just need a gasket and new bolts to install - but it will cost significantly more to go this route.

The Alternator seal is a likely culprit, known to leak, can be done, and probably should be done while you are there anyway. Pop off the drive pulley, remove the seal and install a new one. There is a seal installer and driver (don't know the P/N's) that people have purchased and used before to install the new seal. If you are creative and careful, I'm sure you can figure out how to do it without the special tools.

While you are in there, you should de-gunk your intake runners & valves. Replace all the gaskets and seals for the oil & fuel system, and see how your alternator is doing. Also replaced the crush washers on the banjo fitting that feeds the R/H Turbo (where the pressure switch is attached to), and check the tightness of the L/H Turbo Oil Feed Line fittings.

Good luck!

 

I have question, if the oil cooler housing or filter assy. is leaking will it fill up the area in valley under alternator? My doubts are based on the layout, as there is a distinct partion. Consequently the oil will have easy access to flow down from the front of the engine. This accumulation in the valley, in my opinion, will only happen if there is oil squirting out of the housing or from the shaft seal.

Would like to se your thoughts.

 

Thank you! I agree that it has to be the alternator drive seal. I've since found the part number for the seal, 07Z 903 107, and will descend into the V10 valley in the near future. I also found this previous post on the same topic that pretty much covers all there is on the alternator drive seal: https://www.clubtouareg.com/threads/o6-v10-tdi-oil-leak.289159/

 

Thanks for your input.
I have had the "honor" of replacing the seal twice in 5 days yeaaaah baby.. all because of one, failed rebuilt alternator and two, trying to hammer the darn seal in.

To my amazement, when i initially jumped into the "valley of death" the area around the seal was surprisingly clear of any oil, just residue, even the shaft was clean. The only reason i figured out the seal was leaking was it had small tears in the outer seal surface.

After 3 years, i think i have to jump back in, as i see oil again. But this time i have the seal setting tool (original) and plus as a foresight, i changed the bolts that hold the egr tubes. So hopefully the job will be a minutely easy.

In my last endeavor, i had kept all the EGR pipes and cooler off the engine and started it. After 5 min of idle, when i saw no oil leak, did i put all the stuff back. It was a little extra work, but still better than having to remove everything if there was a leak. I intend doing the same routine again.

I like your idea of running it before reinstalling the EGS mess!
Reinstalling that seal really is a tricky part, I understand how much easier it will be with the tool. I just used a large washer and the fine threaded pulley bolt to pull the inner seal into place. I don’t see how there’s any way to hammer it in.
I wish VW would redesign the seal to have

Thanks for your input.
I have had the "honor" of replacing the seal twice in 5 days yeaaaah baby.. all because of one, failed rebuilt alternator and two, trying to hammer the darn seal in.

To my amazement, when i initially jumped into the "valley of death" the area around the seal was surprisingly clear of any oil, just residue, even the shaft was clean. The only reason i figured out the seal was leaking was it had small tears in the outer seal surface.

After 3 years, i think i have to jump back in, as i see oil again. But this time i have the seal setting tool (original) and plus as a foresight, i changed the bolts that hold the egr tubes. So hopefully the job will be a minutely easy.

In my last endeavor, i had kept all the EGR pipes and cooler off the engine and started it. After 5 min of idle, when i saw no oil leak, did i put all the stuff back. It was a little extra work, but still better than having to remove everything if there was a leak. I intend doing the same routine again.

continuing my earlier reply….redesign the seal to have a spring tensioner inside the seal to cinch the seal tighter on the shaft.
I’ve been in the valley of death four times between my two V10’s. It’s a frightening journey.

 

I like your idea of running it before reinstalling the EGS mess!
Reinstalling that seal really is a tricky part, I understand how much easier it will be with the tool. I just used a large washer and the fine threaded pulley bolt to pull the inner seal into place. I don’t see how there’s any way to hammer it in.
I wish VW would redesign the seal to have

continuing my earlier reply….redesign the seal to have a spring tensioner inside the seal to cinch the seal tighter on the shaft.
I’ve been in the valley of death four times between my two V10’s. It’s a frightening journey.

After banging the **** out of the seal using replica tool the first time around, and still having the leak. I designed this contraption. This is my seal setting tool. The brass sleeve is just the perfect size with little to no play, so when i tighten the bolt into the shaft it pushes the old seal (to make sure force is uniform) onto the washer which then sets the seal. Outer one i still had to use the replica tool.

This time around, i will use the original tool. But still set the seal usimg the bolt method. Just the diff. being the bolt will go through the original tool.

 

Thank you! That’s a complex tool.

 

Its quite simple. I am not sure why VW had to make a tool that had to be hammered for setting a seal. Engine in or out, there is hardly space for a solid wack. They should have atleast designed something that pushes the seal like tightening a bolt.