Alternators.. inline 4 engines

[t25adict]

Would anyone know which engines VW Seat Audi used the alternator with the big spring under it.

It's the ones that bolt up for belt tension, but you have to compress the spring to change the belt then tighten the pinch bolt.

I know was used on T4 1.9 TD / Na engines.
Some AAZ diesel had them and some of the 1.6/1.8 petrol had them.

[Aidan]

if you mean this Link to classic parts T4 Belt tensioner

then it says 1.8PD code and AAC 2.0 code which were early T4 petrols

I found it by looking at parts catalogue for T4 as you suggested that, finding part number for the only one that shows a spring rather than a round tensioner and image googling the part number but parts catalogue already told me PD and AAC code engines, the 1.9 diesels have the normal tensioner set up

[cobblers]

Mk3 golf GTi AGG with aircon does, but for some reason I had to swap to a traditional alternator setup when I fitted that engine in my van.

[Aidan]

You need access to Etka with ATP search function to reverse lookup the vehicles that a particular part is fitted to. Obviously VW dealers have that facility so if you have a friendly TPS you can ask them to look it up for you. Without dragging an old winxp laptop out of storage and booting that I can't do it as whilst Win10 does allow Etos still to work, the old versions of ETKA that we all had back in 2006 are not Win10 compatible and the online catalogues are based on Etos which doesn't have the old ATP function

[t25adict]

It's this type.

[t25adict]

I quite like this setup and have been thinking to go back to this type on one of my cars that currently has to the sprung tensioner system.

[Dueller]

My ahu had this fitment on my Vento

Made a tool for it too, using a chopped ring end of a 13mm spanner and a length of steel, tucked under the fro t panel under tension and held it there while I changed the belt