A/C noise

[phillev]

Hi all, I've noticed that from stone cold my air con has started making what can only be described as a groaning noise when I switch it on. Sounds just like a lowish groan that lasts about a second then all is normal. It all seems to be working fine with cold air from the vents and if I turn it off then on again it's all normal with no groan, as I say it seems to happen when everything is cold and unused, say overnight.car has only done 5k and is a 70 plate with the digital temperature settings. Thanks for any help.

[Chris Boddum]

Sounds like a normal AC system that is slightly undercharged. Mine does the same after I willingly undercharged the system ever so slightly (as an experiment to see if it would help performance while AC is on - for anyone wondering, negligible).

[Wiz201]

Mine has been fine, it sounds a little loud when first starting up but not groaning. I have the fan on inside recirculate so it can cool the interior quicker and isn't fighting with warm air coming in from the outside.

[phillev]

1 hour ago, Chris Boddum said:

Sounds like a normal AC system that is slightly undercharged. Mine does the same after I willingly undercharged the system ever so slightly (as an experiment to see if it would help performance while AC is on - for anyone wondering, negligible).

I haven't noticed any difference in performance and it seems very cold once up and running even in the plus 30 temps we've been having, as I said it only does it if the car has been left a long while such as overnight.

[Derek.w]

What it sound like with just a moderate fan speed?

I leave AC filter out and try it then if ok replace filter.

[phillev]

6 minutes ago, Derek.w said:

What it sound like with just a moderate fan speed?

I leave AC filter out and try it then if ok replace filter.

Definitely coming from under the bonnet and fan is at the lowest speed. 

[TonyHSD]

These noises can be from the radiator fan itself and not the ac compressor. Next time before you turn ac on for the first time in the day best to open bonnet and ask someone to turn ac on while you are watching the fan starts along with ac compressor, try to locate the noise watching closely but be extra careful not to touch the blades. 👍

[Derek.w]

You can hold a screwdriver against AC compressor then fan housing putting your ear close to handle but be careful not to slip with the screwdriver.

[phillev]

1 hour ago, TonyHSD said:

These noises can be from the radiator fan itself and not the ac compressor. Next time before you turn ac on for the first time in the day best to open bonnet and ask someone to turn ac on while you are watching the fan starts along with ac compressor, try to locate the noise watching closely but be extra careful not to touch the blades. 👍

Car is going to be left for a week while I'm away, I'll have a listen when I'm home, cheers.

[phillev]

Just typical, car has been left since Monday and after getting in it at trying the air con today it was totally fine.... Isn't that always the way?

[Derek.w]

Dont worry gremlims will come  back at some point.