A/C noise
 

Hi,

Does anybody recognise this noise?
https://youtu.be/h4Zwtg9ZB_o
The dealer has no idea whats causing the noise.
The system is vacumed and filled with 770gr gas.
The noise disapears when te AC is switched off.

What is done/new:
-new idler pulley
-new alternator bearings
-new serpentine belt and pulleys
-new distribution belt, and pump (twice)
-new powersteering pump + fluid
-new engine mounts
-new ac compressor
-new condensor
-new pressure sensor (AC circuit)
-new expansion valve

Everything looks right, hp pressure seems ok, no errors in vida.
Just that noise that is going up/down with the revs.
It seems that the noise enter the cars interior through te presurelines and the evaporator.

The car is a my2009 v70III, 2.4d

Anybody an other idea? :confused_smile:

No idea what it is but I have a similar noise! Does it stop when you turn the a/c off? I have assumed that it is a bearing somewhere......

I had the same noise after fitting a new compressor. the clutch on the original one seized which is a common issue. I had a local company who I know to be very good fit an OEM one and I was left with this noise. He thought it was due to low gas but the levels were correct and trying to over fill it didn’t help neither did a second compressor. Ended up living with it as car was due to be upgraded.

The noise disappears when the AC is turned off.
I don't really think it's a bearing issue, my personal thought after changing all the parts that i mentioned above is that something is resonating.
I really don't have any idea where I can find the solution. I've spent hours and hours searching for something that I can't find.

It's a Volvo!
Likewise mine whines, up and down with the revs, so it is obviously from the a/c mechanical system and is speed related. Comes only with the a/c on. So either belt, clutch or a bearing. It does occasionally stop but only for a short while.
Very odd.

I replaced all that stuff, every bearing ( pulleys, idler, alternator bearings, powersteering pump, compressor, coolant pump, distribution pulleys etc.....)

Are you sure that's not the steering pump?
What colour is the power steering fluid?

When I bought the car (2 years ago), the power steering was filled with red colored fluid. Also the AC condensor had a leak. At first I repaired the condensor and the system was filled with gas -> The sound apeared.
A few days later I flushed the power steering system with new green fluid with the right specs (not original Volvo), I still had that noise. A day later I replaced the powersteering pump with a new one, and I replaced the alternator bearings, and fitted a new idler pulley, new tensioner and a new serpentine belt. Result was that I still had that noise. Two weaks later I fitted a new distribution kit and a new pump with the same result.
A year later I replaced the compressor with a new one, still no result

What about alternater? It's only obvious under the extra load from the a/c. A/c off, noise gone. A/c on, noise returns.

Alternator has new bearings, slip ring, regulator and brushes.

Does it have a new clutch pulley?
Has the alternator pulley been tested?

I guess you mean the clutch pulley from the compressor? Yes, it came with a new one.
The alternator pulley is also new (ina) and is tested.

Thanks for all the people who share their thoughts.:liebe028:

No I meant the clutch pulley on the alternator.
If a non clutch pulley has been fitted to the alternator, it will stress the belt and other pulleys and create noise.

The exact part number of the pulley fitted to the alternator would be useful to confirm.

The pulley on the alternator is a clutch pulley (INA), it's a new one, and is tested. (using screw-driver to turn the fan in one direction).

Part number of the pulley INA 535 0121 10

Have you looked at belt alignment? There will be a change in belt load with a/c on that might exaggerate any belt misalignment.... try spraying belt with some silicone spray before driving and see if noise disappears.

I haven't checked the alignment using a tool, on the first sight everyhing seems ok. Is it possible that the alignment isn't right? Is there room for misallignment? The alternator can only be possitioned in one way, the same for the powersteeringpump and the compressor. Same for the driveshaft pulley.

You say you had the condenser repaired and the noise started . It sounds like you may have introduced some debris into the AC system . This can cause the noise you have . Try getting an Air con specialist to flush the system . speak to a few AC specialist for an opinion and you may find one that has experienced the same problem It might work and worth a try as that noise would drive me crazy . good luck and let us know hat you find .

When I bought the car, the ac didn't work. The condensor appeared to have a leak so the system was empty. So i have no idea what sound the ac made before the repair.
I can't believe there is debris in the system, in the oil there was no debris, is was pure oil.
Problem here in Belgium is that every local garage calls himself an ac specialist. In reality they have a fill station that vacuums the system and refill it, and thats it.

It's very difficult to find the reason of this problem, Is it a problem of the ac system? Is it a problem of the power steering pump that is amplified when the ac is on, is it a resonation? I really don't know.

The car has been diagnosed by the dealer, an a Volvo specialist, both have no idea what's the problem.

take the accessory belt off and run the engine for 1 minute. sounds like belt rub

It is unlikely to be belt rub as the belt runs with the air on on or off and the noise only there when the air con is switched on.

Watching this thread with interest. Mine is doing exactly the same thing.

I had the same noise since a few days after a "fast and long" 100 km @ 150km/h highway drive in heat. It's only audible on low rews / low speed. Drives me crazy....

Bye the way AC works fine.

Please let us know if you have the solution to cure it.

My a/c makes a similar noise on start up but after 2-3 seconds it goes completely.

Based on an experience with a totally different car, so not as useful as specific experience with a Volvo, but I had a chronic screeching sound which everyone was telling was belt slippage. However it turned out to be a failing pulley and it only screeched when the air con was on or the steering was on full lock or when there was a heavy electrical load. The fault and the symptoms lay in the extra load on the belt when these systems were taking power through the belt and the extra load on tyhe pulley caused it to shriek. Replacing the pulley cured the entire problem but initially everyone was sure it was belt slippage. It was a Peugeot and it took a French mechanic in backwoods France to smile and say that it was a well known fault, well known in France anyway!

Thanks for the help, will check it with my volvo mechanic.

In the meanwhile I found multiple videos in youtube with the same issue but unfortunately without any useful solution.

My Dad's V70 is making the exact same noise as yours & it stops when the A/C is turned off. It leads me to think there's something wrong with the compressor, but people have replaced them & it didn't solve the problem... :confused_smile:

Update us if you find out what's wrong. :regular_smile:

Had my 2007 S80 2.4d now for over 10 years. mine has made this noise since day one, never had any mechanical issues in its 140k apart from consumables.

aircon works perfect, never been regassed, never needed it.

maybe its just one of those things! dont worry about it

I have a similar noise - removed the serpentine belt to see if i can prove what it is - before I did that when I put a metal bar against the air con compressor, alternator and steering pump and hold to my ear it sounds worst at the alternator...

With the belt removed the noise has gone. So that narrows it down to alternator, steering pump, air con compressor or belt tensioner.

The serpentine/aux belt tensioner is really noisey and rough - and the alternator may also be a little rough - belt and tensioner on order to see if that fixes it first.