Aygo 2012 - 15 sec screeching noise upon AC cold start

[Bv9]

Hi. I have an Aygo Ice from 2012. When turning on the car from cold, no issue.

However, if I turn on the car from cold and switch on the AC immediately, the car makes a screeching sound from the fan belt area of the engine. It lasts only 15 seconds then quietens down.

Also if I drive the car for 5 mins from cold and turn the AC on then no noise.

Any ideas what could cause this screeching noise only from the AC being switches on immediately on cold that lasts for 15 secs max? Tx

 

[APS]

Slack or worn auxiliary belt. The AC compressor use a significant amount of power. When cold the belt is not as grippy and may slip and squeal. Tighten or replace the belt. 

[TonyHSD]

Replace the belt if you have been hearing the noises for some time now and the belt hasn’t been replaced recently, it is most likely worn out. 

[Bv9]

Hi there. Ok Auxiliary belt changed a day ago. Thought this would have solved it but started the car again this evening after 7 hours of sitting idle and the screeching was back! Difference this time was that it was quieter and increased with revving the engine. Only lasted though in the first couple of mins of setting off and then nothing. I was wondering if the AC compressor has a different belt to the Aux belt? Any other suggestions? Tx

[Bv9]

Hi there. Ok Auxiliary belt changed a day ago. Thought this would have solved it but started the car again this evening after 7 hours of sitting idle and the screeching was back! Difference this time was that it was quieter and increased with revving the engine. Only lasted though in the first couple of mins of setting off and then nothing.

So I was wondering could it be:

1) AC Drive Belt?

2) Water pump belt?

3) Alternator?

4) Clutch?

5) AC compressor itself?

Any other suggestions? Tx

[Billyboy81]

Recheck your adjustment on the belt.

[TonyHSD]

Get a bottle of water and open the bonnet before your cold start or whenever it’s most common this event. Start the engine , turn AC ON and go outside the car when the screeching starts pour some water onto the belt and if the noise disappear means your belt is not properly tightened, worn out or not of a high quality and can’t make a good contact with the pulleys and when under load is slipping. 👍

[DBRA]

I owned a (different) car in the past that made that type of noise due to a slipping magnetic clutch in the A/C compressor. It always happened just after I started the engine, and after a few seconds the sound was gone and it wouldn't reappear until the engine cooled down completely. It was more of a grinding noise and not the squeaking noises you get from belt slippage. I lived in a warm country, so the A/C was on always, and I drove like that for quite some time until I sold the car.

Perhaps you can locate the noise with the hood up and exclude the belt. I would then suspect the clutch.

I was told the clutch is dependent on tolerances, and companies servicing A/C systems can sometimes adjust the tolerances by inserting or removing shims below the clutch. The A/C compressor may need to be removed for that (with unloading/loading the refrigerant), so I am not sure if that is economic or that you'd rather replace the compressor. 

I would consider to drive past an A/C servicing company and just ask for their opinion.

 Good luck.

[Mooly]

I had something similar when I had a Corolla TSport. In it's latter years it developed a loud screech from cold. Mine was caused by a noisy pulley bearing (can't remember now the layout and whether it was the tensioner or not).

The fix was easy and long lasting i.e it 100 % cured it for the remaining years and several thousand mile after doing this.

All I did was get a long bladed flat screwdriver and rest it on the pulley centre and let some engine oil run down the shaft onto the pulley. I guessed at least some would find its way into the bearing. A couple of paper towels caught most of what ran down and out the pulley face. Instant fix. Happy days.