Air con making strange sound.

 

Had diagnostic check yesterday, mobile mechanic, checked pulley, belt and bolt etc, all ok, found good gas pressure (9.3) and no fault codes.

Decided to reset the vent flaps in the hope it may help...but no avail.

 

Comes on after a couple of miles, then varies in sound level following revs up and down.

 

Also, there is no sound under the bonnet only in and around the dash area.

 

Give it 30 seconds or so...was hard to capture the sound.

 

Noisey air con sound

 

Thanks for listening

Anyone else had this sound or similar ? Wondering if I might try getting it regassed, even though the pressure seemed ok

 

Any thoughts appreciated

 

cheers

Mine does exactly the same thing.  I came to the same conclusion as you, that a regas might sort it, but haven’t got around to doing it yet.  

Thanks for the reply, it was getting a bit lonely on my own  but at least now I know there is at least 2 of us with the same condition

 

Hoping it isn't a serious problem, will post up results if and when I can get a regas done.

 

cheers

Edited 1 March, 20197 yr by harryrope

Look forward to your results, I’ve got a few other bits and pieces to sort before I get round to the air con. 

I can't directly compare aircons but that sounds like a motor bearing - probably a fan.

 

Thanks, I agree with you...but not sure of which fan...or where. When AC switched off but blower engaged, all is well, regardless of temp.

 

It does sound bearing'y to me...got new suspension Bilstien B6 to get fitted first, then look into a regass.

 

cheers

I'm not so sure, mine "groans and moans" with quite a similar noise.  It has done this since I bought it, so for 3 years. However, when I first got it, it was really bad, really noticeable when idling, and regassing did help it even though it was only about 20% or less down on refrigerant (i.,e. it still had 80% charge), being a 5yo car.  It did sound like a bearing or pulley to me too, but  having followed it, and mine improved with gassing, as well as it disappearing when no ac demand, I don't think it can be.  In my case, I think it must be related to the compressor operating.

Edited 4 March, 20197 yr by TheClient

On 26/02/2019 at 20:35, harryrope said:

Give it 30 seconds or so...was hard to capture the sound.

 

Noisey air con sound

Recording from inside the vehicle doesn't help at all. Raise the bonnet and follow the sound around compressor and accessories belt.

Any good mechanic should be able to pinpoint the noise in 15 minutes with a stethoscope for mechanics.

2 hours ago, RicardoM said:

Recording from inside the vehicle doesn't help at all. Raise the bonnet and follow the sound around compressor and accessories belt.

Any good mechanic should be able to pinpoint the noise in 15 minutes with a stethoscope for mechanics.

 

Thanks, it's a fair point, but the sound has been located to behind the dashboard, just right of the info centre...the mystery is what is making the noise and why.

 

I'm looking for a parts diagram to see what lurks behind the dash area...maybe its a valve for the air con or something....engine revs effects it definately.

 

cheers

See illustration below.

Edited 4 March, 20197 yr by RicardoM

Mine makes a cyclicl whooshing/howling noise like a drafty window or chimney in a storm, approx 0.5hz frequency (every é seconds) can only hear it when car is stationary as otherwise the road/engine/transmission noise drowns it, it stops if I press the "Econ" switch, definitely from the same area of the dash.

 

I would never have been aware of it as its not really intrusive but my aircon did not work for the first 6 months I owned the car and when I changed the pump and got it working I noticed the noise, using the Econ switch confirmed it is definitely aircon/climatronic related and its nothing from under the bonnet.

The only motor item I can see in the partsex is the main fan - item 1 - part number for RHD 3C2820015F.  It's fitted to a wide range of Skodas so finding a replacement should be fairly easy.

I would ask anyone else with functioning aircon to see if it makes a noise that they may not have noticed before, sit with the engine idling in a quiet environment, Climatronic on AUTO, probably better once engine is at temperature, top vents closed, listen carefully around the unit then engage the "ECON" function, does it sound any quieter? Do you hear a new noise when Econ is switched off allowing the aircon to blend the air again?

 

On mine I'm pretty sure when the aircon pump was not working (system charged, being commanded to work but not pumping) using the ECON setting switched off the light on the AUTO button, you could toggle back and forth between the two by pressing the ECON button, now the system is working and making the whooshing noise using the ECON switch lights up ECON but AUTO remains illuminated, the only way to stop AUTO is to change the fan speed setting, is this how the system should work?

Thanks for all the input thanks for Diagram Ricardo

 

Just to clarify -

 

-The noise only starts when engine is warmed up

 

-the fan blower is quiet when the air con is switched off, fan still rotating/blowing air but no noise....

 

-As soon as AC button is pressed, noise returns ??

 

There is a valve (11)...Im thinking maybe regassing renews the lubrication and helps valve etc???

 

seems strange that it changes sound, with increased engine revs...

 

If it was the blower fan...why would it not do it when AC is switched off...??

 

cheers

 

 

Edited 4 March, 20197 yr by harryrope

Noise is simply due to low refrigerant, and pressure is no indication of refrigerant quantity. Low gas leads to cavitation in the compressor pump which is the noise. Don't allow it to run too long like that as it can damage the pump. Get it regassed by some place with a proper automatic a/c servicing machine i.e. one that weighs the gas and oil extracted, maintains a vacuum for at least 15 mins to check for leaks and dry the system and refills it by weight with new gas and oil. Most kwikfits, F1 autocentres etc have this machine and are much cheaper and more reliable than dealers. Do not use a mobile service that just uses gas bottles and pressure gauges. Refill quantity measured by weight and the extraction of old gas and vacuum phase is critical.

 

Most should give you a report printed out from the machine as to the weight of gas and oil extracted and refilled.

Edited 4 March, 20197 yr by xman

Mine and I suspect the OP's noise is definitely not coming from the pump but from inside the centre console where the Climatronic system is.

 

Mine makes the noise even when the pump is being worked at minimum circulating loading as shown by VCDS, the noise is no different at 5% or 100% duty cycle and is not coming from the pump. As the OP's rises with engine revs pump noise is more plausible but from where its coming from it must be something to do with the circulation of refrigerant.

36 minutes ago, J.R. said:

Mine and I suspect the OP's noise is definitely not coming from the pump but from inside the centre console where the Climatronic system is.

 

Mine makes the noise even when the pump is being worked at minimum circulating loading as shown by VCDS, the noise is no different at 5% or 100% duty cycle and is not coming from the pump. As the OP's rises with engine revs pump noise is more plausible but from where its coming from it must be something to do with the circulation of refrigerant.

 

Your whoosing noise is not the same as the OPs compressor noise.

 

Typically when you turn your engine off, with the a/c having been on, you may hear residual whoosing and gurgling coming from the evaporator which is the cooling element in the dash). This is because some circulation of refrigerant is still happening due to residual pressure in the condensor and the expansion valve located on the bulkhead slowly releasing it to the evaporator), it is the sound of the refrigerant passing through said expansion valve, and  "boiling" in the evaporator (i.e. the phase change that gives the cooling)

 

You may have a particularly noisy expansion valve, sometimes due to debris, which may make it cyclic. You should flush an a/c system if you change a pump that has failed as there's likely to be debris and contamination released further downstream, and affect the operation of the expansion valve, which in bad cases would then need cleaning or replacing.

 

Also tends to be noisier with low refrigerant levels.

 

You may have heard a similar sound from your fridge/freezer at home when the motor stops.

Edited 4 March, 20197 yr by xman

Thanks for the explanation, makes sense so thats another non problem I can forget about!!!

 

There was no debris or contamination from the old pump, I stripped it after removal and it was as good as new, no wear, clinically clean until all the pistons and the half moon bits sort of erupted in my hands and fell amongst the sawdust etc, I binned it then and never did find why it wasnt functioning unless the replacement solenoid valve (Chinese) I fitted was not doing what it should, it seemed to react OK on a bench test and none of the two internal passages were blocked.

Thanks all,

Xman, cheers for that info, I'm convinced with that explanation....will get it sorted soon as...shocks can wait wee bit longer.

 

Will update after regas

 

All the best

 

Harry

Update -

 

Thanks to all advice, input

 

Had the regas done today at Kwik fit, £59.99 - took about an hour, done about 175 miles so far and it seems sorted.

 

I changed the cabin filter (carbon) and ran antibacterial bomb yesterday.

 

Very pleased, hope this helps others

 

Cheers all

 

https://youtu.be/8QsoIC3Q3UE

 

 

23 minutes ago, harryrope said:

Update -

 

Thanks to all advice, input

 

Had the regas done today at Kwik fit, £59.99 - took about an hour, done about 175 miles so far and it seems sorted.

 

I changed the cabin filter (carbon) and ran antibacterial bomb yesterday.

 

Very pleased, hope this helps others

 

Cheers all

 

https://youtu.be/8QsoIC3Q3UE

 

 

 

Did they give you a report how much gas was removed? 

He said they dont do printouts, but the manager was very helpful and he owns an octy vrs, which probably helps

 

....he showed me the figures on his sheet and maybe I should of asked for a copy.

 

I think 531 went back in??

Hi,

Is your strange sound like this sound? Can you comment please.

Thank you in advance.

 

you

@Levcho

Hahaha! She'll be coming round the mountain when she blows...