Best of my knowledge and experience....
Drop donor TDI entire front sub frame, move the lot over.
Wiring is quite different, same location and trunking from the dashboard distribution panel through the firewall into the ECU box on the front of the wheel arch. But thats about it, everything else is all over the place. TDI fuse box is very slightly higher than the petrol ones for some reason.
I'm gonna go on a limb and say the connections from the ECU to the main distro panel in the dash under the steering column is the same. So if you take the entire engine side harness from the donor it should plug and play. There are no extra special bolt holes/through holes/mounting locations on a TDI over a petrol one. Rad pack is the same as any turbo P80 car AFAIK so can just stick with that lot.
Just resurrected my diesel, did a pretty much full engine rebuild after experiencing a flattened cam shaft + 2 slightly low on compression cylinders, originally suspected bent rods, but turned out to be gummed up piston rings due to me using veg/WVO during summer for the last 5 years. Also got the fuel pump rebuilt as was doing some weird things. Currently running it in again at 280k miles! MPG is up, but vibrations are up too, suspect my collapsed DMF is not helping the situation and maybe an engine mount has gone, as has been sat on one mount + a jack stand for about 2 years!
Runs clean as though, no smoke unless on it. The diesels never do less than 40 mpg, into the low 50's if you are careful. A handy thing in these times of crazy fuel prices.
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