climate control / air-con problem! HELP before the weather gets hot again!!!

[air121005]

before we start.....i've tried searching but can't find a specific thread / answer to my issues but what i have found.... i have tried the pollen filter, it is dirty but plenty of air is getting through and coming out the vents as normal as fan speed works as it should and the temp works normally getting the air hotter

anyway, at the lowest temp setting i get warm to frickin hot air coming out the vents depending on the ambient temp.

so thought i needed a re-gas, went to halfords and got one of their recharge kits consisting of a can and hose with a gauge.......for £50

i thought i'd first measure the pressure of the system first before attaching the hose to the can as reccommened and followed the instructions....... however the gauge says that the system is holding about 70psi which is well into the "warning" zone on the gauge!!

anybody know what the PSI should be within the CC / A/C system??

so i'm assuming as its holding so much pressure it doesn't need a re-gas or do i still need to empty some of the contents of this can i got from HFs to inject some of whats inside (nitrogen i think) to make the air cool again?

not sure i want to add to 70psi and risk popping the system and ending up with no system at all.......any help and guidance much appreciated before the weather gets hot again!!

 

[DEAN0]

before we start.....i've tried searching but can't find a specific thread / answer to my issues but what i have found.... i have tried the pollen filter, it is dirty but plenty of air is getting through and coming out the vents as normal as fan speed works as it should and the temp works normally getting the air hotter

anyway, at the lowest temp setting i get warm to frickin hot air coming out the vents depending on the ambient temp.

so thought i needed a re-gas, went to halfords and got one of their recharge kits consisting of a can and hose with a gauge.......for £50

i thought i'd first measure the pressure of the system first before attaching the hose to the can as reccommened and followed the instructions....... however the gauge says that the system is holding about 70psi which is well into the "warning" zone on the gauge!!

anybody know what the PSI should be within the CC / A/C system??

so i'm assuming as its holding so much pressure it doesn't need a re-gas or do i still need to empty some of the contents of this can i got from HFs to inject some of whats inside (nitrogen i think) to make the air cool again?

not sure i want to add to 70psi and risk popping the system and ending up with no system at all.......any help and guidance much appreciated before the weather gets hot again!!

The system does not contain nitrogen - it should have a correctly measured amount of refrigerant.

The plate under the bonnet of my tdi sport says it is R134a refrigerant and that there should be 550g +/- 25g in the system.

If there is too much refrigerant in the system it will run hot because there is no room for the refrigerant to expand and contract as it does its job.

I would get it proffessionaly re-gassed - it's about £40 to have done. That way you know it's correct.

 

[air121005]

this says refirdgerant all over the can & R134a........sure i read the word nitrogen on the can.........

anyway, so if i let some pressure out it will cure my problem?

 

[Neo]

Was your A/C running when you checked the pressure? I think the low pressure side will read higher when the system is inactive.

Do you know if the compressor is working?

 

[air121005]

car was running.....c.c. on full speed, cold setting.....as per the instructions on the can

been thinking.......if i let out pressure from the system back down to within the safe limits as per the gauge on the re-charge kit would this get cold air blowing again?

my other thought and the more logical the more i think about it is...... that as Deano stated, the refrigerant needs to expand to work so for the system to work the PSI needs to be lower ~30 PSI according to the can....
so because the refrigerent has dissipated over the years this has allowed the PSI to creep up to 70 PSI........so if i release the pressure i will then have to use the re-charge kit to replace the lost gas i think......

.....at £50 this could be an expensive experiment .......thats providing releasing the pressure doesn't fk the whole system and its components up!

has anybody tried re-charging the system themselves?

 

[Neo]

Hmm, 70psi does seem high then! I`ve been told it`s more like 40 in a normal a/c system.

But surely as the volume dissipates over the years the low side pressure drops?

 

[air121005]

thats what it says on the can...between 25 & 40 psi depending on the ambient temp at the time.

re. the pressure,
if there isn't any refrigerent in the systen the a.c compressor will keep compressing what little there is but to do that it must reach a higher psi......well thats how i understand it!

 

[shazo]

them cans am sure they were selling at 20 pounds each on ebay and in shops, halfords always is a jip. and kwick fit do a free check and refill for 40 quid.

 

[splitpin]

I would take the can back to the shop!

 

[Leigh15]

if there isn't any refrigerent in the systen the a.c compressor will keep compressing what little there is but to do that it must reach a higher psi......well thats how i understand it!

No - it's a sealed system

My advise would be to get it looked at professionally. Kwik Fit for example do a recharge service for £45 IIRC which is guaranteed to improve your A/C for you don't pay.

Just guessing and letting refrigerant out and then indiscriminately putting more back in is a fast track way of screwing up the A/C system. There's a good reason why those A/C refill aerosols are about to get banned.....

 

[DEAN0]

re. the pressure,
if there isn't any refrigerent in the systen the a.c compressor will keep compressing what little there is but to do that it must reach a higher psi......well thats how i understand it!

Unfortunately the refrigerant is not just refrigerant. It is a mix of refrigerant and a kind of oil to lubricate the cc compressor. Too little refrigerant will scrap the compressor.

The compressed air dryers we have at work are refrigerant based. They do all sorts of wierd things if the refrigerant fill is not correct.

The +/- 25g tolerance on the 550g is there for a reason - it keeps the system within its working limits.

When you get a refrigerant circuit re-filled they first have to evacuate the system to make sure there is nothing in it. Then they put a bottle of R134a on some accurate scales and measure the 550g going in to the system.

 

[cowtc]

I have exactly the same issue, the first time I plugged it in, the reading went really far into the red zone (very high PSI), the second time I did it after putting the climate control to Low and running the car for about 10 mins, it was still in the red zone but not as high as the first reading. Did you have any luck with this and what did you do in the end?

 

[air121005]

as it goes, car was booked in today for a re-gas / air-con service......was going to post in here anyway as it isn't fixed

they checked it, new refridgerent, serviced it (what ever they do) and when they were checking it worked realised that the when you ask for cold air (dial down) the relay that controls the compressor for the air con doesn't kick in the cold air basically......

apparently the compressor is fine.......was going to plug in vag-com and hopefully there will be faults to tell me what needs fixing/replacing

 

[D-Power]

Let us know how you get on. I think I may have a similar problem-had the air con regassed but still no cold air. Engine revs do not change when i press the Econ button on/off so I suspect (and hope!) its an electrical thing

 

[lee_fr200]

just take it to seat, they charge 59.99 for the full air con service, they did mine for free when it went in today

 

[cowtc]

I think Seat will charge the air con service and then charge how ever much it takes to fix the problem which could be loads if they take ages to find it

 

[D-Power]

Lee-both myself and the OP have aircon problems that aren't from the gas or system leaks etc-so I dont think its worthwhile spending £60 to have local seat apprenctice kid bung more gas in.
Looks more likely to be electric problems so fuses coming out over the weekend and fault code searching if that fails, as cowtc says, then i might get an idea of how much its going to cost....eek!

 

[cowtc]

Did you have any luck on this? I might be getting mine checked at the local garage soon (whenever I get time off work)

 

[air121005]

Did some searching and couldn't get to the bottom of it....

Apart from starting to replace components of the system I out of ideas....

 

[techie]

Lee-both myself and the OP have aircon problems that aren't from the gas or system leaks etc-so I dont think its worthwhile spending £60 to have local seat apprenctice kid bung more gas in.
Looks more likely to be electric problems so fuses coming out over the weekend and fault code searching if that fails, as cowtc says, then i might get an idea of how much its going to cost....eek!

The local SEAT apprentice isnt allowed to operate the AC equipment unless he is IMI approved. From this month its now illegal for anyone not quailified to work on an AC system and venting R134a to atmostphere can cost you a 100k fine. These can will soon vanish as it will be illegal to use them.

Any technician who knows ac systems will be able to diagnose the cause of the problem.