Air conditioning help

[pol]

Hi All,

My air conditioning has never worked since buying this 1.8t sport (1999).

I've been reading as many forum posts as I can find and managed to find that the smaller of my 2 cooling fans was seized. I replaced it yesterday in the hope that the AC would start working but no cold air at all.

I switch the AC on, there is an increase in revs and a slight clunk. I assume this is the compressor engaging. Both front fans spin when the AC is switched on.

No obvious faults found in VCDS.

Where can I start looking? It's not the big green fuse on top of the battery. Both fans work and it sounds like a compressor clicks in.

Help! It's too hot for this ****!

Cheers,

Paul

 

[<tuffty/>]

Had it re-gassed?

<tuffty/>

 

[pol]

I haven't yet. I figured it should still work a bit without getting regassed? If it needs regassed and doesn't work at all, doesn't that mean it'd have a massive leak?

 

[<tuffty/>]

They can check for leaks... it will be picked up as part of the re-gas procedure...

<tuffty/>

 

[pol]

But then I'd have to pay to have the leak fixed and a failed regas? Just wondering if there is any more DIY things I can look at / test first.

 

[Chillout]

But then I'd have to pay to have the leak fixed and a failed regas? Just wondering if there is any more DIY things I can look at / test first.

Think quick fit is £50 and if it's not cooler it's free I think ,I have all the kit and I wouldn't do it for as little

 

[pol]

Think quick fit is £50 and if it's not cooler it's free I think ,I have all the kit and I wouldn't do it for as little

My first thought was take it to Kwik Fit but after reading similar forum posts I had talked myself out of it! Might still be worth a go.

So do you reckon thats a good first port of call? Might be lucky and it just needs regassing? It isn't cold at all. No difference to just having the blower on at the moment so no sign of AC.

 

[RGL]

Sounds like it needs a refilling. You don't necessarily have to have a massive leak. Even if you have a little bit left inside, it wont blow cold. Mine holds up with one refill the whole season (late spring, summer and hot part of autumn) and I figure it would hold up even much longer. I however suspect that it leaks during winter when the compressor is switched off due to cold outside temps. Have heard it might be due to gaskets or whatever drying up in the system and starting to leak when the system is not switched on.

None of the filling processes have ever shown me any notifiable leaks either, it just leaks when it is not used for long periods of time. Don't know why exactly. But two times I've refilled it, there's always been some pressure left inside and it won't blow anywhere near the cold it should (basically blows outside temperature air) until I get it refilled. So refill and checking for leaks is the start. Hope this helps.

 

[mattupnorth]

There's a voucher for kwikfit at the moment so only cost me £39 last weekend...it didn't work so I got a refund. Can't really complain at that!! My issue points to the high pressure sensor, which I'm going to try and replace later today!

 

[crazyjay91]

There's a voucher for kwikfit at the moment so only cost me £39 last weekend...it didn't work so I got a refund. Can't really complain at that!! My issue points to the high pressure sensor, which I'm going to try and replace later today!

I may sound STUPID, but when you remove the high pressure sensor, will all the gas leak out?

 

[pol]

There's a voucher for kwikfit at the moment so only cost me £39 last weekend...it didn't work so I got a refund. Can't really complain at that!! My issue points to the high pressure sensor, which I'm going to try and replace later today!

It's been filled up but I didn't pay as apparently it didn't work. They said it started to work but then it didn't? He was saying the compressor isn't turning... I'll need to check that myself..

Do you get a noise and a change in revs if the compressor isn't working?

 

[rupe]

Sounds like it needs a refilling. You don't necessarily have to have a massive leak. Even if you have a little bit left inside, it wont blow cold. Mine holds up with one refill the whole season (late spring, summer and hot part of autumn) and I figure it would hold up even much longer. I however suspect that it leaks during winter when the compressor is switched off due to cold outside temps. Have heard it might be due to gaskets or whatever drying up in the system and starting to leak when the system is not switched on.

None of the filling processes have ever shown me any notifiable leaks either, it just leaks when it is not used for long periods of time. Don't know why exactly. But two times I've refilled it, there's always been some pressure left inside and it won't blow anywhere near the cold it should (basically blows outside temperature air) until I get it refilled. So refill and checking for leaks is the start. Hope this helps.

It leaks out because the systems in cars are full of hoses and joins everywhere which are subject to alot of vibration and as you say the seals and things can become dry and leak when it's not in use, it's good practise to run the system periodically through the winter months aswell to take the oil which the gas moves around the system lubricating it.

Generally you put a u/v dye in the system before refilling it and look for leaks with a lamp in automotive stuff and the reason it won't get as cold even if their is only a little gas lost due to a leak is to do with the refrigerant itself, if theirs not enough in the system then the pressure won't be right and in turn it won't be evaporating at the correct temperature.

Hope that makes sense

rupe.

 

[RGL]

Wow, thanks dude for explaining it! It seems as I had the right idea, just didn't know the ins and outs and wasn't fully sure. But still thank you for confirming my thoughts and explaining it further!

 

[basil brush]

If you can hear your compressor kick in ( which YOU can ) there is gas in the system , however not enough to cool your incoming air !
The system has a pressure switch which cuts the compressor in case if a de gas situation as the PAG oil in the gas lubes the compressor .
Have the gas topped up , which I did last week for £25 and it's ****** freezing

 

[pol]

After the Kwik Fit top up, I get cool air con but only for about 10 - 15 minutes from starting the car from cold. It then cuts out.

Any ideas where to look?

 

[basil brush]

Yep, look for a garage with a uv dye kit
They will inject dye into the system then with special glasses and a uv light inspect the whole system looking for the escaped dye , hey presto leak found

 

[pol]

Yep, look for a garage with a uv dye kit
They will inject dye into the system then with special glasses and a uv light inspect the whole system looking for the escaped dye , hey presto leak found

Cheers Basil.

So that sounds like how it'd behave if it had a leak? Kwik Fit were saying it was holding the refrigerant fine, it just cuts out.

I'll look in to the UV stuff.

 

[<tuffty/>]

Any fault codes?

Could be the compressor if its been out of action for long enough

<tuffty/>

 

[pol]

Any fault codes?

Could be the compressor if its been out of action for long enough

<tuffty/>

No fault codes.

 

[newbster]

hi pol

could be a number of things, but you need to take it to someone who has the correct equipment to diagnose the issue, which is a set of gauges, and who know what they are doing, which is not quickfit. they are great for doing a top up, and the no charge if it doesn't fix it is great. I got mine done for free after fitting a new condenser because they did not know what they were doing.

if the compressor comes on and stays on, check by watching the centre plate of compressor, could be not enough refrigerant, but we have already ruled that out, or weak compressor, or the pressure control valve inside the compressor stuck open, common fault on the style of comp used.


could also be a blockage in the high pressure line, or the metering valve, so not enough refrigerant is being pumped around, this sometimes causes the comp to trip on high pressure

blockage on low pressure side usually causes comp to trip on low pressure


the only way to find out is to hook up some gauges.

you can't diagnose faults on these engines without Vagcom, same with A/C, you need the right diagnostic tool

you can do the spanner work yourself when you have found out what the problem is

where are you? there is a good guy in solihull

hope the above helps


edit

decided to read all the post again
the above is still true, but, as it runs for 15 minutes and then cuts outs, makes it a little trickier
could be overheating, the fans are both working, so not that, could be the condenser not cooling enough, but if it does it whilst driving, its proably not

leaves a couple of things

the pressure control device inside the compressor is not working correctly, or the metering valve at the evaporator coil is not working correctly

either way you need a man with gauges

 

[pol]

hi pol

could be a number of things, but you need to take it to someone who has the correct equipment to diagnose the issue, which is a set of gauges, and who know what they are doing, which is not quickfit. they are great for doing a top up, and the no charge if it doesn't fix it is great. I got mine done for free after fitting a new condenser because they did not know what they were doing.

if the compressor comes on and stays on, check by watching the centre plate of compressor, could be not enough refrigerant, but we have already ruled that out, or weak compressor, or the pressure control valve inside the compressor stuck open, common fault on the style of comp used.


could also be a blockage in the high pressure line, or the metering valve, so not enough refrigerant is being pumped around, this sometimes causes the comp to trip on high pressure

blockage on low pressure side usually causes comp to trip on low pressure


the only way to find out is to hook up some gauges.

you can't diagnose faults on these engines without Vagcom, same with A/C, you need the right diagnostic tool

you can do the spanner work yourself when you have found out what the problem is

where are you? there is a good guy in solihull

hope the above helps

Thanks for that! Very helpful information.

I'm in Eastbourne, East Sussex - so quite far away from Solihull. I'll look for a local air con expert. I knew Kwik Fit were rubbish but also knew they'd do it for free and then I could maybe rule something else out!

Thanks,
Paul