ALH TDI Injection Quantity Seals

Well, the B99 summer to D2 winter switch wasn't so nice to the seals on the injection pump on the TDI. Considering that it's a 2003 model with 118k on it, they did their job well. The last leak was the pump's head seal and that one was an interesting fix. I got the stuff from Dieselgeek and made sure that I ordered extra viton seals since I figured I'd pinch at least one. I found out that cleaning the seal land with a piece of safety wire made sure that all of the old seal was removed...learned that the hard way. For this leak, I ordered the funky tool from Metalnerd and the seal kit from Peter over at TDIParts.com.

I wasn't real sure about messing with the IQ block since it has the possibility of causing a runaway engine, but I had to dig in because it was leaking pretty badly. (insert memories of V8 Cat at almost full throttle) I checked the IQ with the VAG-COM after I got home from dropping off the little one at school the other day and it was at 2.8-3.0. Reading around on the TDIClub forums is beneficial, but there are enough red herrings in the forum threads to fill an ocean. If you enjoy that kind of thing, go for it, but I've worked flat-rate, and a bunch of "oh nooo, you can't do that!" style stuff just pisses me off.

So, here we go with the flat-rate get'er done fix.

I was working on a car that had been sitting a while. It doesn't appear to make that much difference other than you're going to burn your hands if you're doing this on a waiter...and if you're reading this and working flat rate - you shouldn't be working on this car.

Get brake cleaner, a 3/8 drive ratchet, 17mm wrench, adjustable wrench, hammer and small chisel, special funky socket, T20, and T30. Clean all of the leaky diesel crap off of the pump with the brake cleaner. Now, if you've read the stuff on TDIClub, it'll tell you to take off the wiring harness at the pump. That's BS for this pump and the funky special tool won't work on the screw that they put on the corner of this harness plug...so screw it.


Next up, get a scribe or a box cutter and make a mark around the edges of the IQ block where it hits the pump body. There's a ledge there that you'll see. Outline the IQ block with the scribe. Mark around the upper curve and the lower curves that you see in the photos below.


Next up - make two marks with the hammer and chisel. Now, don't go bangin' the crap out of this stuff because it's pretty soft. I made my marks where I could easily look down on them to line them up. I made them deep enough that I could easily see them.


Now take a 17mm and an adjustable wrench and remove the fuel line/banjo bolt and washer. Not much fuel will come out, but get your rags stuffed under the pump because the next steps will get your feet wet.

Pull the top three bolts and the funky special bolt and remove the top - if you need to replace the upper seal, and really, if you're going to spew D2 on the floor, why not just replace the upper seal? It's probably best to replace the upper seal and then put the bolts back on hand tight.

Now you can take the lower cover bolts off and rotate the piece enough to get the new seal in. Make sure that you get the pin (you'll see it) back into its spot back down in the pump. It won't fit back together unless it is put back into its spot.

You can now move things back to where the scribe marks say that they should be and put the bolts back in. Check the scribe marks against the chisel marks just to make sure that everything is in place. Being a bit off on this part could cost you an engine. Tighten the lower bolts, upper bolts and reinstall the banjo bolt. Brake clean off the diesel that spilled and you're done.

I did this and the IQ was bouncing from 2.8-3.0 before and was 2.8 when I was done. I may try the hammer mod just to get it up to 3.0 or a little higher, but it'll do for now. Total time messing with this was under 15 minutes from start to finish. Do this at your own risk - ymmv.