The air con compressor on my Astra 1.6 16V 1997 has developed a noise a bit like an old fridge. I have stopped using the A/C as a precaution. Does this mean big bills or just a regas??
Any advice would be much appreciated.
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Sounds like the compressor. I don't think there are any other moving parts. If you take it off to examine it, you will need a re gas anyway. I would carry on using it till it breaks, and then fit a re con unit or second hand compressor.
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Just seen Richards reply, and I would advise against just running it till it breaks completely, as it can cause a hell of a mess inside the system. Not to mention the fact that if it runs a serpentine belt, when it seizes it will take the belt with it.
Would you run a noisy engine till it goes bang?
You may be lucky with a second hand unit, but it's the same as buying a second hand engine, you just don't know what it's like until you run it. Plus, you need to find what sent your current compressor south, otherwise the replacement will go the same way.
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If it's noisy, then it's broke (or will be soon).
In addition to the compressor, you will also need a new filter/drier and expansion valve. As you don't know what has caused it's demise, and how much debris, if any, is in the system, you want to be sure that whoever fixes it gives it a good going over to make sure it doesn't happen again.
Compressors fail for a number of reasons:- A slow leak has caused a loss of gas, therefore a loss of lubricant. A blockage has occured somewhere and has restricted gas flow (expansion valve), thereby restricting lubricant flow. The fan has packed up, thereby causing high pressures as the gas gets hotter. The valve in the compressor has got stuck. Or the compressor has just plain worn prematurely.
Compressors are normally about £400 for a genuine Delphi (but not from Vauxhall), expansion valve £50, filter/drier £50, plus labour, seals and recharge. You can buy a recon one, but my experience with these has not been good, and it will still probably cost about £250, so you won't save a great deal.
When whoever gets the work recovers your existing gas, make sure they weigh it, then you can tell how much has been lost, thereby telling you if it has a leak or not. They can then take it from there and look for other causes. They will also need to have a good look for any debris if the compressor has started to break up. If there is any, then it will need a proper flush, otherwise it will all get sucked back into your new compressor.
If you want to do the work yourself, come back to me and I'll talk you through it, because you'll still need someone to recover your gas and weigh it, then come back later and recharge it. So it may be easier to get them to do the whole job, then if it all goes belly-up when/after it's been recharged, then it's someone elses problem.
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Its probably the bearing at the front of the compressor,which is commonly a big needle roller.If it can be removed,then this can often be done in-situ,without regassing.If not then you need a new compressor,and you need it now!
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Robin, the bearing you refer to is the clutch bearing, and this will show as noisy only when the a/c is off, as the clutch is being turned by the belt, but the compressor is not. It is true that this can sometimes be done in situ, but have you seen the Astra installation? Plus you will need a special puller and a press to get the bearing out. If the noise is when the compressor is on, then the clutch turns at the same speed as the compressor, therefore the bearing you refer to isn't actually turning, meaning the noise is from inside the compressor, where there are bearings, but all behind the main shaft seal. There are also 5 pistons and a variable wobble plate, as well as valves, which can all go bad.
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Thanks for all the advice given; I'll start looking for an A/C specialist to investigate.
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The bearing in question turns all the time,it can hardly help doing so,as its fixed to the pully wheel.
But when the clutch is engaged its locked up to the other bearings in the compressor and therefore makes much less noise.
The one on my 405 was not specially hard to replace,but the Astra one may,of course,be less accessible.
A garage will typically just change the compressor,but this may not be necessary.
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