Diagnosing a tick tick noise in the proximity of the PAS pump on a 2007 2.0 TDI (BRE) engine

[Rob69]

Thanks for clearing that up, i didn't know they had the constant drive compressors fitted back in 2007. I've more recently had to look at my FIL's 2013 2 litre tdi yeti with a ticking noise, that was also from the ac compressor, which as far as i could see with a mirror (tight down there!) seemed to have three radially spaced drive plates riveted onto the pulley, the rivets wereloose and a fair bit red rust dust around the pulley so looked like it had been worn for some time. Presumabely this is also a constant drive modulating compressor. He got that changed by skoda under warranty so i never got to see the compressor removed.

These engines use a different design of AC compressor to the longitudinal 3B with a constant drive modulated delivery system which places a variable load on the drive system without the in/out thump of a magnetic clutch compressor, so it goes quiet with the AC off?

[Fodens]

Replacing the Air conditioning pump solved the problem and the engine all sounds normal again. There was a small amount of play in the pulley and a definite grinding noise with the old part which the garage certainly had not seen before. Sadly only solved by replacing the whole air conditioning pump so not cheap but worth it to get rid of the noise.