Probably a really stupid question, but...."clink" noise?

al dm · Nov 6th, 2022, 20:20

If I leave my car stationary and idling on the drive, every 20-30 seconds or so (I haven't timed it yet), it seems to make a kind of "clink" noise. It sounds to me like a solenoid butterfly valve of some kind opening.

Does anyone know what this is? EGR or something like that?

The car has zero DTC codes and drives great. I just haven't heard this kind of noise on any other car I have owned and I am intrigued as to what it is....

GrahamBrown1 · Nov 6th, 2022, 20:23

It’s not the AC kicking in and out is it?

al dm · Nov 7th, 2022, 08:59

Quote:

Originally Posted by GrahamBrown1

It’s not the AC kicking in and out is it?

Hmm....I am not sure. It could be. Climate control is normally set to auto.

I guess the way to test that would be just to set the climate as low as it will go so it continually demands AC, and then see if the noise disappears.

al dm · Nov 7th, 2022, 10:05

OK, so after a little bit of testing, it is definitely related to the climate control.

I took the car out for a drive to get it all up to operating temperatures, then on my drive with the car idling I set the AC to LO and started messing with the fan control.

With the fan at zero, there is no clink noise. If I turn the fan up, then it makes the noise. If I then turn it down again, it makes a very similar noise but softer. Presumably a valve or flap somewhere opening and then closing again. It could be the noise of a relay switching - but I think it's too loud for that. Sounds more like a metallic flap opening/closing - maybe caused by an electromagnet turning on/off.

It looks like the noise is caused when the car demands the fan to turn on. I guess it could also be the AC compressor rather than the fan, as if there is no fan demand, then presumably the car will turn the AC compressor off?

So now I know roughly what causes it, the next question is, is it normal? And if not, where is the part that makes the click noise and can/should I replace it. The heating and cooling works perfectly, so I am happy to just leave it as I can only hear it at idle with the door or window open, but if it's something easy, then why not sort it out? And besides, I like to play with stuff like this....

Any ideas?

al dm · Nov 7th, 2022, 10:20

Forgot to say, but the noise seems to come from the engine bay rather than the interior.

After a bit of Googling, it seems to be a known "normal" thing and is caused by the AC compressor clutch cycling on and off as Graham said.

There are some discussions saying that if the noise if frequent (like every 5 seconds or so) then it's a sign that the AC system might need re-gassed. Probably not an issue right now as we are going into winter, but maybe something to think about in the spring...

Stu B · Nov 7th, 2022, 11:15

AC compressor cycling - it’s normal, as is a dribble of water underneath from the bulkhead area AC drain when you park up.

yostumpy · Nov 7th, 2022, 22:22

Ok, leave the fan running, and just press the AC button to turn off, so fan only. If no clicks then it’s the AC .

Nov 6th, 2022, 20:20	#1
al dm Member Last Online: Apr 22nd, 2024 09:10 Join Date: Oct 2018 Location: Guildford	Probably a really stupid question, but...."clink" noise? If I leave my car stationary and idling on the drive, every 20-30 seconds or so (I haven't timed it yet), it seems to make a kind of "clink" noise. It sounds to me like a solenoid butterfly valve of some kind opening. Does anyone know what this is? EGR or something like that? The car has zero DTC codes and drives great. I just haven't heard this kind of noise on any other car I have owned and I am intrigued as to what it is....

Nov 6th, 2022, 20:23	#2
GrahamBrown1 Register Keeper - S80, P2, and P3 Last Online: Today 22:35 Join Date: Feb 2013 Location: North Yorkshire	It’s not the AC kicking in and out is it? __________________ Previous -03 S40, 04 V70 D5, 04 V70 D5 Sport, 05 V50, 07 S60 D5, 09 V70 D5 R design, 12 XC60 DrivE, 15 V60 D3 VEA Current- 05 XC90 D5 Exec, 12 XC70 D4 AWD Se Lux, 14 S80 D3 Se Lux

Nov 7th, 2022, 11:15	#6
Stu B Master Member Last Online: Today 21:39 Join Date: May 2016 Location: Cheshire	AC compressor cycling - it’s normal, as is a dribble of water underneath from the bulkhead area AC drain when you park up. __________________ 2017 V60 CC D4 AWD Polestar

Nov 7th, 2022, 22:22	#7
yostumpy Senior Member Last Online: Today 22:31 Join Date: Mar 2021 Location: Gravesend	Ok, leave the fan running, and just press the AC button to turn off, so fan only. If no clicks then it’s the AC . __________________

Nov 7th, 2022, 10:05	#4
al dm Member Last Online: Apr 22nd, 2024 09:10 Join Date: Oct 2018 Location: Guildford	OK, so after a little bit of testing, it is definitely related to the climate control. I took the car out for a drive to get it all up to operating temperatures, then on my drive with the car idling I set the AC to LO and started messing with the fan control. With the fan at zero, there is no clink noise. If I turn the fan up, then it makes the noise. If I then turn it down again, it makes a very similar noise but softer. Presumably a valve or flap somewhere opening and then closing again. It could be the noise of a relay switching - but I think it's too loud for that. Sounds more like a metallic flap opening/closing - maybe caused by an electromagnet turning on/off. It looks like the noise is caused when the car demands the fan to turn on. I guess it could also be the AC compressor rather than the fan, as if there is no fan demand, then presumably the car will turn the AC compressor off? So now I know roughly what causes it, the next question is, is it normal? And if not, where is the part that makes the click noise and can/should I replace it. The heating and cooling works perfectly, so I am happy to just leave it as I can only hear it at idle with the door or window open, but if it's something easy, then why not sort it out? And besides, I like to play with stuff like this.... Any ideas?

Nov 7th, 2022, 10:20	#5
al dm Member Last Online: Apr 22nd, 2024 09:10 Join Date: Oct 2018 Location: Guildford	Forgot to say, but the noise seems to come from the engine bay rather than the interior. After a bit of Googling, it seems to be a known "normal" thing and is caused by the AC compressor clutch cycling on and off as Graham said. There are some discussions saying that if the noise if frequent (like every 5 seconds or so) then it's a sign that the AC system might need re-gassed. Probably not an issue right now as we are going into winter, but maybe something to think about in the spring...

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)