Hello, i recently purchased a new (for me) car. The car is  audi a8 4.2 petrol quattro, but it turned out it has issues with the air conditioning. After i sent it to a garage, the mechanic said that i need to replace the compressor. Long story short - i don't live in the same country, so i am trying to gather as much information as possible before sending one to him from where i live.  He couldn't provide me with the part number for some reason.

Does it have to be from exactly the same car/year/engine ?
Does it matter if it's from a diesel engine or not?

Apologies for the questions, which may seem simple to some. I have no idea and it's always better to ask. 🙂

Best regards,
Boz

Getting one from.a similar aged and similar mechanicals as yours would be better.