Most of us here will know that VW state that in order to change the Tandem pump on a V10 engine, you must first remove the engine! It sounds easy when you put it like that doesn't it
Having been reliably informed that it is possible, although a bit fiddly to change the pump in situ I have been presented with the challenge so here we go!
First off... put your Touareg in the lowest air suspension position. You'll be climbing onto the engine bay!
Also, put some cardboard down onto the floor in line with the front wheel and under the engine. You will be leaking oil and diesel onto it.
One V10 engine!
Remove the dipstick, cover and boost pipe for the right hand side.
No, you can't see the tandem pump yet. It's buried down on the back of the cylinder head.
Here's the throttle body. It has an EGR pipe bolted to the back of it with 2x M8 Allen headed bolts. Access to them is limited and not helped by the loom mounting spike on the bulkhead. I moved the spike a little to help.
I started off with the normal allen key on the lower one but it was too tight on the top so I used a handy little snap-on ratchet.
There is a metal gasket on the EGR pipe flange but it's held on with tangs so it shouldn't drop off/out. I removed it later on once the throttle body was out of the way - just in case it wanted to try to disappear!
Now remove the four M6 long allen bolts that secure the throttle body to the inlet manifold. You don't need to pull them out, just undo them so that the throttle body comes away.
The throttle body seals onto the inlet manifold with an o-ring so you don't need to worry about any gaskets there.
There is a small loom connected to a black mounting bracket that the lower two M6 long bolts pass through. It runs behind the throttle body. Gently prize it away and the clip will come out without damage.
Also, the EGR pipe bolts to the same support bracket with a small torx bolt which needs to be removed.
Once the throttle body is moved out of normal position, you can get to the electrical connection and vacuum pipe. Be CAREFUL with the electrical plug. I have seen countless plugs destroyed by people trying to use tools to release these. It's easy if you do it this way... push the connector further on BEFORE you try to release the clip with your other hand and it will come off easily. You will not get it to release easily if you just try to release the clip. These clips are designed to be under tension from the seal.
Once these have been disconnected, you can remove the throttle body out of the way.
I hooked the vacuum pipe up over by the bonnet hinge so that it wasn't in the way.
The EGR pipe has restricted movement due to being supported lower down next to the air filter box.
Remove the right hand air box outer part (as you would as part of a service) by removing the two long plastic torx bolts (twist 180į and pull up), pull the feed pipe forwards to release it and undo the two top clips to allow the upper part of the outer box to come away, not forgetting the extra breather pipe which is hiding half way down the side facing away from you! Someone has broken mine
Now remove the air box outer and you have access to the EGR pipe bracket bolt.
The EGR pipe bracket bolt is another torx bolt and it is angled with the cylinder head so expect it to be fiddly.
Once removed, the EGR pipe has move 'give' and you can pull it up a bit and gain clearance to the back of the cylinder head.
Now you can see the tandem pump and some of the pipes going to it.
The top one is the servo pipe and just pulls off (gently please!). Don't lose the rubber sealing tube which gets left behind. I also uncoupled the vacuum pipe above it where it meets the 'T' so that I could pull the pipe completely out of the way and hooked it up near the washer bottle cap.
The next pipe is the diesel feed pipe. It has a spring clip which you can either use pipe pliers for or a small pair of maul grips. I used the latter as I did have my pipe pliers to hand. At the same time as prizing open the clip, you will need to get a tool under the end of the fuel pipe to push it off. I used a trim took and levered against the metal servo pipe above it - gently that is! It comes off fairly easily. There will be a bit of diesel spilt here but not much. Have a cloth to hand and stuff it down behind the pipe to catch the diesel.
Once the fuel feed pipe is free, you can move it up out of the way and hook it up so that it doesn't leak any more and doesn't get in the way.
Now you have the fuel outlet pipe to disconnect. This is the pressure side.
It's a 17mm banjo bolt and the washers are free to be Lemmings should they get the chance!
You can't see this bolt. I took this photo while I was putting things back together to ensure that I had both washers in position before tightening it up.
I used a stubby 17mm spanner to loosen it as there isn't enough room for a normal length spanner in there.
More fuel will leak here and there's not much you can do about it hence the cardboard under the car.
At this point, you will need to be on top of the engine on your knees. Not fun but that's the way it is unless you're 6 ft 10"!
Using both hands, slowly loosen the banjo bolt taking care to not drop the washers or bolt. I think that it's stainless and the washers are aluminium so a magnet will not help you here. You have been warned
Once out, you can concentrate on the three bolts that secure the pump to the back of the cylinder head.
There are two M8 allen bolts (size 6 allen socket with 1" extension) and one M6 10mm headed bolt.
I started at the lower one which is the most difficult to get to.
Just reaching down to find it resulted in a load of oil all over my fingers... so my suspicions of this being the cause of the oil leak were confirmed.
I had my extendable magnet to hand here as it's very difficult to get to this bolt, let alone catch it when you try to remove it. I almost dropped the allen key socket at this point but caught it with the magnet and was then able to remove the bolt by finger tips.
No photos as you can't see it!
The upper M8 bolt is above where you remove the fuel outlet pipe banjo bolt from. Feel for it with your fingers or the allen socket and it's easy to get to. Remove as with the other one.
The M6 10mm headed bolt is below the boss that the banjo bolt screws into. Remove this and the pump is ready to come out.
Again, no photos of these sorry, it's all done by feel.
The pump is now ready to push back off the cylinder head. Oil will leak from it and the head... nothing you can do but mop up later.
The pump is a tight fit between the bullhead and the cylinder head coming up but by wriggling it around, there is enough room just!
Once out... it'll look a bit like this...
Oilly mess that it is!
On this V10, it's the original pump to the engine as suggested by the date stamp of 2005 and the part number ending in 'B'.
Refitting is - as always - the reverse of removal
Line up the drive of the replacement pump to match the old one before anything else. If it doesn't line up with the camshaft, it won't go into the cylinder head.
I slid the replacement pump (suffix 'D' part number) down behind the cylinder head BEFORE putting the gasket on. The new gasket is metal but delicate and it's almost impossible to have it attached to the pump while you squeeze it down past the rocker cover. I got the pump down behind the cylinder head (it'll sit on the exhaust and can't drop any further) before adding the gasket to it and then offering it up into position.
I also used a small trick of adding some sticky tape to the end of the allen socket to hold the allen bolts for the pump so that they didn't drop off when re-fitting.
The rest is fairly easy so good luck!