Making it Run
IP seals and timing belt replacement
I had some trouble getting the TDI to start after wiring up all the wires from the ECU. I thought that I could get the IP to prime and that was the reason it wouldn’t start. So I thought that because the engine had sat for over a year that maybe the seals had dried out. So I order up a seal kit with a Viton head seal and got to work. Well after I got everything back together and tried to start the engine, I still had nothing. So then I went and double checked my wiring. It turns out that you have to hook up the power wires to the IP before anything will work. After I fix this stupid mistake everything worked great. I primed the IP with a little compressed air (center below). The engine sounded good and everything looked right in VCDS. With the engine running I could start replacing the timing belt.
The timing belt on these engines is not a simple thing to replace. You need to have special tools and a computer with VCDS on it. You can see from the picture below that the last time the timing belt was done the mechanic used the mark and pray method. This is not the right way to change a timing belt on these engines.
Because I didn’t have the right tools to do this job, I made them J (above center). I looked the cam using some 1/8” flat bar and some utility knife blades (below center). Then I drilled a small hole in the cover behind the cam pulley (below right) and used a punch to remove the pulley. The other method would be to use a special puller that I didn’t have. Once the new belt and rollers were installed I started the engine and timed it using VCDS. More detailed instructions on how to replace a timing belt on a AHU TDI engine can be found at TDI Club.