Hi guys,

I'm hoping to utilise all of you collective knowledge to try and figure out what's making my air-con noisy.

Basically, when my car's running, the climate control is all nice and quiet with just the usual fan noise and actuator movement noise. When I put my air-con on though, the compressor kicks in as normal and things get nice and cold but there's a noise that seems to come from the centre console and what seems like around the drivers footwell. The noise is hard to describe but the speed of it increases with engine revs and I guess, if I had to say it sounds like something, I guess it sounds like a bicycle pump being used really quickly. Its not really noisy but just enough to be annoying...

Anyone got any ideas as to what it could be? I'll take any suggestions whether they're accurate or not... as marketing people would say, lets brainstorm and think out of the box here... :tosser:

In the centre console and the driver's footwell is where your interior parts of your air con system are located but there's no continually moving parts in there apart from the usual interior fan so the noise you have is within the gas of your air con system and increases with engine speed from gas/ fluid circulating from your compressor.

So, you may have had a bad refill of your air con last time which is causing pulsing in the system of gas/ liquid

Again, a hook up to check system low and high pressures with system running will tell you a lot. Like a cup of tea, the mixtures (in this case of gas, fluid and oil) have to be just right otherwise the results are similar to British Rail tea

Deckchair5 said:

In the centre console and the diver's footwell is where your interior parts of your air con system are located but there's no continually moving parts in there apart from the usual interior fan so the noise you have is within the gas of your air con system and increases with engine speed from gas/ fluid circulating from your compressor.

So, you may have had a bad refill of your air con last time which is causing pulsing in the system of gas/ liquid

Click to expand...

Ha ha, thanks Decks, just what I wanted to hear. I've got a mobile air-con guy arriving shortly I figured that might be the case so I thought that a de-gas, lubrication and a re-fill would be the best starting point!

Cheers for replying, matey. It's appreciated and I'll let you know how it goes...

Greggers

There you go then, should be sorted within an hour. Have a look over his shoulder and make a note of the low and hi pressure readings with system running for reference later and write them down so you dont forget. It'll take a few hours running to get to proper system balance and efficiency though

my air con doesnt seem to work, i put in on and nothing doesnt get cold ??? any ideas???

Well, mine is now officially sorted since the de-gas, lubrication and re-fill

What is happening when you switch the air-con on? Can you hear the electro-magnetic clutch kick in on the compressor? It's quite loud so you should be able to hear it if it is kicking.

If you can't hear it, it could be that there is no pressure in your system. There's a safety feature which prevents the compressor running if there's no gas in the system to avoid damaging it.

It could also be worth checking all of the air-con fuses if you're not getting any lights on the air-con button.

The light comes on, and you can hear the revs drop abit, bit there's no noise, and no coldness either

Oakley28 said:

The light comes on, and you can hear the revs drop abit, bit there's no noise, and no coldness either

Click to expand...

I think the revs are meant to increase, not drop when you put the aircon on. This is to compensate for the extra load on the engine that the compressor puts on.

I'd get a mobile air-con guy out to have a look at it. He'll be able to check the pressure and check for leaks. It doesn't cost much and might be a good second step once you've ruled out something silly like a blown fuse...

how would i check for the fuse? and how would i know if its blown?

Oakley28 said:

how would i check for the fuse? and how would i know if its blown?

Click to expand...

I'm sure that Deckchair5 has posted all of the fuses involve din the aircon system, have a search and see if you can find them. Once you know the numbers and their locations, you can just pull them out (when the car's not running!) and check to see if the metal strip embedded inside the plastic is continuous. If it's burnt out, you'll know it.

Too be fair, fuses don't usually blow for nothing so you might need to get an air-con guy out anyway...

Search and yee shall find...

cheers mate.... ill have a look see

Oakley28 said:

cheers mate.... ill have a look see

Click to expand...

No worries mate. Wish I could help more!

yeah me too, its in for a service on friday so may just point it out to Fiat

Greggers said:

Well, mine is now officially sorted since the de-gas, lubrication and re-fill

What is happening when you switch the air-con on? Can you hear the electro-magnetic clutch kick in on the compressor? It's quite loud so you should be able to hear it if it is kicking.

If you can't hear it, it could be that there is no pressure in your system. There's a safety feature which prevents the compressor running if there's no gas in the system to avoid damaging it.

It could also be worth checking all of the air-con fuses if you're not getting any lights on the air-con button.

Click to expand...

Pressed the air-con button today when driving, and it makes like a click sound when you turn it on, but it just doesnt get cold at all.

If the A/C switch lights up when you select it, engine tickover rises and internal fan goes onto setting 1 if it's in the off position then power is getting through the switch so the most common cause of compressor not firing up is a lack of gas pressure.

So I'd hook up A/C gauges and check your static gas pressure. Too low and it won't allow the compressor to start up. Air con engineer will check your system pressure usually for free in 5 mins

Well, my air-con is being a pain again

It's started being noisy again and it sounds a bit like a cross between a pump being used extremely quickly and playing cards in bicycle wheels. The sound is most noticable when you come off the gas and the revs drop as the sound seems to lag just behind. The sound speed increases and decreases with revs.

I'm starting to think that a) I've got an air-con leak and that b) the sound is something to do with the gas being circulated through the system. I'm wondering what could be causing it but I suspect that maybe the compressor is at fault?... I'd like to rule out other options first though so I was wondering if anyone could post a picture showing the air-con system of the 2.4 on eper? It doesn't ever work for me and I'd like to see all of the different components involved

Cheers!

I've been doing some looking into this and I think that maybe my expansion valve is "whistling" as the compressor pump, making it sound like a very quick bicycle pump.

if it is the expansion valve, whereabouts is it? is it expensive to replace?

Cheers for any help you can give!

Been looking into this with my trusty stethoscope and it looks like my compressor is the culprit... will have to keep an eye on it and try to get it changed under my warranty agreement

It looks like the compressor has completely failed now The clutch kicks in so the pressure is good but there's just no cooling, so it looks like the gas just isn't getting compressed

Anyone know what's involved if I wanted to change the compressor myself? I take it that I'd need to change the reciever/dryer and the expansion valve as well (along with the relevant o-rings)? Once done, I'd get a mobile air-con guy out...

Or maybe I'll just get a garage to do it for me

Compressor clutch kicking in but no gas flow might well be a blockage, quite common at the expansion valve. Need to get an air con engineer to connect gauges up to the HP and LP side which they'll often do free of charge as it only takes a minute. Then you can see what's going on

Very high HP and very low LP would give the game away

Bicycle pump noises indicates gas isn't flowing steadily and the gas has to go through a very narrow venturi at the expansion valve which is easily blocked