Passat tdi engine type

I have a 2001 130 bhp pd passat 6 speed manual.

What is the easiest way to see if it is an Avf or Avx engine?

What difference does it make?

Just gone over 100k miles so gonna get a few things done TB good service. Car is going strong so gonna keep for at least another year.

Is there anything else to watch out for?

That detail should be contained on the sticker in the manufacturers manual that came with the car. It will tell you the engine code, color code and all that Jazz. Check there

The engine code is the first three letters on the drivers side bulkhead under the bonnet. It's a black sticker. If the vehicle has AC look at the AC pipe under the bumper on the driver side. You will see it is close to a silver colour container. Cable tie it away slightly as it wears a hole in this unit and it's hassle to sort out.