Air Conditioning compressor noise behind dash?

Willber · Post by **Willber** » 26 Oct 2022, 03:54

When the ac compressor kicks in, I can hear a strange (and often varying) sound which feels as if its coming from behind the driver side dashboard (UK driver side). Its hard to describe the sound but its not a gurgling sound or screech. Im trying to work out of the sound is due to the compressor or something else, maybe a valve or something? The compressor doesn't make much noticeable noise from the outside apart from the clutch coming in and out.

Any ideas what it could be?

Thanks

93SCMax · Post by **93SCMax** » 26 Oct 2022, 05:19

Does the noise/pitch change based on the speed setting of the fan?

If so, one potential problem I have seen is these older cars start to collect dirt and grime on the fan blades. They can be caked on and off balanced, and then they make noise. The only solution is to drop the fan/motor and clean the blades.

Willber · Post by **Willber** » 26 Oct 2022, 06:02

Apologies, perhaps not clear from my initial post - the sound is only when the compressor kicks in, when it disengages again the sound goes. It is not related to fan speed.

Post by **scot850** » 26 Oct 2022, 10:32

Have you tried to see if the noise is coming from the engine bay with the A/C on?

The only thing that is behind the dash is the evaporator. Have you had the fluid pressure checked in the A/C system recently?

Neil.

Willber · Post by **Willber** » 26 Oct 2022, 11:17

The sound is more like a light grinding type noise more than anything I would say. It does change in pitch sometimes though.

I cant tell from in the engine bay where it is coming from

Yes, its had a regas last year. It has always been like this for 2 years and 20k miles. Im not overly worried but do wonder if the compressor seized then it would cause major damage. For approx £220 i could get a new Nissens compressor