2011 VW Polo 1.6TDi noise on Ac compressor

[jacovt02]

Hi Guys I'm hearing a scratching noise on my ac compressors when my AC is off, when I turn the AC on the noise goes away. A few mechanics have told me that it's dangerous to drive like that as it can contaminate my ac system. I have been driving with the noise for more or less 2 years now but it seems like the noise is getting a bit louder. Is it possible to replace the pulley on the ac compressor or will I have to buy a new unit?

Thanks in advance.

[VAG Fan]

Dagsê Jaco,

When the AC is off, then the pulley runs on a bearing on the compressor shaft. When you switch the AC on, the magnetic clutch binds the pulley to the compressor shaft, which means that the bearing stops turning.

I suspect that this bearing is worn. Whether it can be replaced separately, I don't know. I would think that one can replace the pulley as a unit.

Either way, I am skeptical of your mechanics' comments on "contamination". If your aircon is working, and the noise goes away when you switch it on, I see no way for the system to become "contaminated". The fact that the noise starts when you switch the aircon OFF, tells me that the problem lies outside the compressor.

[jacovt02]

Dagsê Jaco,

When the AC is off, then the pulley runs on a bearing on the compressor shaft. When you switch the AC on, the magnetic clutch binds the pulley to the compressor shaft, which means that the bearing stops turning.

I suspect that this bearing is worn. Whether it can be replaced separately, I don't know. I would think that one can replace the pulley as a unit.

Either way, I am skeptical of your mechanics' comments on "contamination". If your aircon is working, and the noise goes away when you switch it on, I see no way for the system to become "contaminated". The fact that the noise starts when you switch the aircon OFF, tells me that the problem lies outside the compressor.

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I've went to a few ac shops here in Kempton and all of them want to replace my whole system which they quote me for around 20k. If I run with the AC on all the time will that make the bearing last a bit longer? Or will I just make more k*k for myself (sorry for the bad word) ? The AC still work 100% and in this heat makes me quite cool when driving so I don't really want to spend the money for a new compressor, Goldwagen quote me 6k for a new one but they don't even have stock.

[Ashveer03]

First U need to confirm whether the AC has a clutch type or clutchless type compressor.

Vws from around 2003~2012 generally have a clutchless pulley, one of those rubbish plastic ones.

Every broken (in regards to noise) clutchless compressor i have seen, catastrophically broke - contaminating the system.

If it has a clutchless compressor, replacing the bearing isn't as simple as a clutch type system. Most ac "mechanics" won't want to do it since it's sort of an internal bearing. These compressors permanently run with the engine - always on.

U can however replace the clutchless compressor with a clutch type. Iv done plenty on Mk5 generation golfs, It's much more reliable and it seems to work better imo.

If it has a clutch type compressor, then the pulley is a simple bolt on replacement.

Sent from my CPH2371 using Tapatalk

[VAG Fan]

Thanks Ashveer, I didn't know about the clutchless pulleys. My '04 Golf still has a clutch pulley, so I didn't know better.