AC/Climate Control: cools down for about an hour and then warm air

[Traction]

I have a bit of an odd issue.

Given the recent high temperatures I've been using the air con a lot.
It defeinitly works initially because its been nice and cold.

At the weekend I was on 2 long journeys.
After about 50 mins - an hour the car stated to feel warm.
I put the temp to low and fans up full.
It was cool air but the car never really felt cold, still colder than if it was off though.

Does anybody know what this could be caused by?
Also, does anybody know where the temperature sensors are inside the car?

I'm wondering is this issue only because the outside temperature is lower than the past few weeks.

 

[brian1912]

I have a bit of an odd issue.

Given the recent high temperatures I've been using the air con a lot.
It defeinitly works initially because its been nice and cold.

At the weekend I was on 2 long journeys.
After about 50 mins - an hour the car stated to feel warm.
I put the temp to low and fans up full.
It was cool air but the car never really felt cold, still colder than if it was off though.

Does anybody know what this could be caused by?
Also, does anybody know where the temperature sensors are inside the car?

I'm wondering is this issue only because the outside temperature is lower than the past few weeks.

Maybe needs a gas refill


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[Traction]

oh right, I've never had it re-gassed before and it is 13 years old now!

Is this what happens when gas needs to be changed?

 

[brian1912]

oh right, I've never had it re-gassed before and it is 13 years old now!

Is this what happens when gas needs to be changed?

Jeese you’ve done well 13 years lol I’m every couple of years to be honest but yeh if it’s been working fine then blowing hotter air could be out of gas could be the condenser too but if it’s worked fine up too then more than likey needing re gassed


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[Traction]

Jeese you’ve done well 13 years lol I’m every couple of years to be honest but yeh if it’s been working fine then blowing hotter air could be out of gas could be the condenser too but if it’s worked fine up too then more than likey needing re gassed


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great, thanks.
Spotted a new air con re-gassing system in the local garage recently... good timing!

Any idea where the inside temp sensors are?
have always been curious.

 

[brian1912]

great, thanks.
Spotted a new air con re-gassing system in the local garage recently... good timing!

Any idea where the inside temp sensors are?
have always been curious.

To be honest I’ve not a clue I might be wrong but I thought the drivers footwell ?

And I’ve always had my cats re gassed at my local garage safer in my opinion


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[Rusty2k]

Jeese you’ve done well 13 years lol I’m every couple of years to be honest but yeh if it’s been working fine then blowing hotter air could be out of gas could be the condenser too but if it’s worked fine up too then more than likey needing re gassed


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If yours is needing a regas every 2 years then you have a leak somewhere...

 

[brian1912]

If yours is needing a regas every 2 years then you have a leak somewhere...

I use mines nearly every day summer and winter that’s probably how


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[Rusty2k]

I use mines nearly every day summer and winter that’s probably how


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Nope, you have a leak! The fridge in your kitchen is switched on 24/7 and how often does that need a regas?

 

[brian1912]

Nope, you have a leak! The fridge in your kitchen is switched on 24/7 and how often does that need a regas?

I’ve have it serviced by seat themselves about six months they check for leaks to the condenser and pipe work and no leak I had a Honda before this which did have a leak and only lasted a week


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[Rusty2k]

I’ve have it serviced by seat themselves about six months they check for leaks to the condenser and pipe work and no leak I had a Honda before this which did have a leak and only lasted a week


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Okay, so if you don't have a leak then why are you needing regular recharges? The refrigerant gas doesn't get "used" when the AC is switched on... it's a sealed system, just like the engine coolant... you'll only lose coolant if it escapes somehow... you'll only lose your AC gas if it escapes somehow...

Clearly it's not a big leak if you're only needing a recharge every 2 years, but you've definitely got a small amount of gas escaping.

 

[CustardKing93]

Okay, so if you don't have a leak then why are you needing regular recharges? The refrigerant gas doesn't get "used" when the AC is switched on... it's a sealed system, just like the engine coolant... you'll only lose coolant if it escapes somehow... you'll only lose your AC gas if it escapes somehow...

Clearly it's not a big leak if you're only needing a recharge every 2 years, but you've definitely got a small amount of gas escaping.

I've just had my Leon FR regassed and its loads colder now, doing some research and nearly everywhere tells you to regas your AC every 2 years, as well as the refrigerant there is also certain lubricating oils mixed in, which over time, just like engine oil, break down and are now not as efficient. The oil is there to lubricate all the seals, which is why your'e much better off keeping you ac on all the time, even if its hot AC air, it keeps the oils running, keeping the seals lubricated.

 

[Traction]

I've just had my Leon FR regassed and its loads colder now, doing some research and nearly everywhere tells you to regas your AC every 2 years, as well as the refrigerant there is also certain lubricating oils mixed in, which over time, just like engine oil, break down and are now not as efficient. The oil is there to lubricate all the seals, which is why your'e much better off keeping you ac on all the time, even if its hot AC air, it keeps the oils running, keeping the seals lubricated.

before you got the re-gas did you ever notice the A/C reach a point where it was on for a while and then stopped working as efficiently?

 

[Rusty2k]

I've just had my Leon FR regassed and its loads colder now, doing some research and nearly everywhere tells you to regas your AC every 2 years, as well as the refrigerant there is also certain lubricating oils mixed in, which over time, just like engine oil, break down and are now not as efficient. The oil is there to lubricate all the seals, which is why your'e much better off keeping you ac on all the time, even if its hot AC air, it keeps the oils running, keeping the seals lubricated.

As far as I've seen, the only places that seem to push you towards regular recharges are companies that will happily take your money to provide that service. SEAT doesn't recommend this. It would be part of the car's regular service schedule if they did. I can understand a regular check of system health, but if there's nothing wrong then nothing needs doing. I would be surprised if any air con places did the oil properly with a simple recharge as this would require removing the compressor to drain the oil out of it. There's no other way of knowing how much oil is in the compressor other than emptying it.

The main reason engine oil deteriorates is because of it's exposure to air and moisture combined with heat. In a properly sealed AC system these issues do not arise. The biggest problem with AC compressor oil is that the type usually used with R134a refrigerant is hygroscopic so if there are any system leaks it will gradually absorb moisture from the air which can then lead to further problems.

The Mk2 Leon, along with a lot of VAG cars, uses a continually driven compressor design that doesn't have a clutch to turn the compressor on or off. Instead there is a pressure control valve that can vary system pressure and circulation. This allows the system to maintain minimal circulation in the system to ensure the lubricants are being circulated as necessary. As long as the car is used fairly regularly it doesn't require the AC to be run to circulate the lubricants. The system design takes care of that.

My 2010 FR still provides lovely cold air from its factory refrigerant charge. Measured just now on VCDS as 1.5 °C after the evaporator.

 

[Rusty2k]

before you got the re-gas did you ever notice the A/C reach a point where it was on for a while and then stopped working as efficiently?

Do you have a fault code reader? If the climatronic system is shutting down the AC compressor then there are probably fault codes to explain why.

Have you had the system checked over? Most of the third party places that offer AC recharging will do a free check I believe.

 

[CustardKing93]

As far as I've seen, the only places that seem to push you towards regular recharges are companies that will happily take your money to provide that service. SEAT doesn't recommend this. It would be part of the car's regular service schedule if they did. I can understand a regular check of system health, but if there's nothing wrong then nothing needs doing. I would be surprised if any air con places did the oil properly with a simple recharge as this would require removing the compressor to drain the oil out of it. There's no other way of knowing how much oil is in the compressor other than emptying it.

The main reason engine oil deteriorates is because of it's exposure to air and moisture combined with heat. In a properly sealed AC system these issues do not arise. The biggest problem with AC compressor oil is that the type usually used with R134a refrigerant is hygroscopic so if there are any system leaks it will gradually absorb moisture from the air which can then lead to further problems.

The Mk2 Leon, along with a lot of VAG cars, uses a continually driven compressor design that doesn't have a clutch to turn the compressor on or off. Instead there is a pressure control valve that can vary system pressure and circulation. This allows the system to maintain minimal circulation in the system to ensure the lubricants are being circulated as necessary. As long as the car is used fairly regularly it doesn't require the AC to be run to circulate the lubricants. The system design takes care of that.

My 2010 FR still provides lovely cold air from its factory refrigerant charge. Measured just now on VCDS as 1.5 °C after the evaporator.

Ok fair enough pal. I didn't claim to be an expert just repeating what I've read off the Internet somewhere

 

[Traction]

Do you have a fault code reader? If the climatronic system is shutting down the AC compressor then there are probably fault codes to explain why.

Have you had the system checked over? Most of the third party places that offer AC recharging will do a free check I believe.

Don't have a code reader but I might be able to get it checked at local garage.

 

[Traction]

OK, I have some updates and I'm hoping it might make sense.

I got the air con checked.
No fault codes but gas level was almost half.
Got it re-gassed and the air con is definitely quicker to get to temperature.

But it still stops working as well around the 50 mins - 1 hr mark.
This is what I tried last time
Outside temperature was around 19°
I put the temperature all the way down to 16° but it didnt make much difference.
I then put the temperature all the way up to 29° and it got only slightly warmer.
As it was a bit warmer I tried 16° again but it didn't really make much difference.

When I parked up at services I kept the car running for a while.
The car started to get a lot colder.
So it seemed to be working better when engine was idling.

Engine was stopped for about 30 minutes and when I started it the A/C was working well.
It only worked well for another 20-30 minutes.


On the return journey it was a bit warmer outside - about 21.
The Air Con stopped working as well after about an hour, but I noticed that as I pulled off motorway and slowed down that the cabin started to feel cooler.
Similar to before, I left the car run for a bit while parked and it got very cool.

It now appears to me that when the issue occurs, it could be related to engine speed.
I should have tested the performance with the temp set to HI and LO.
Also, I never tested it with Air Recirculation turned on.

Does any of the above point to a specific issue?
I'm wondering if its a compressor issue.

 

[jonny76]

@Traction

Hello mate,

I'm having pretty much the same symptoms you've described in my MY07 Cupra.
My own diagnostic handheld unit picked up a G89 temp sensor fault, and i took the car in to a local specialist, who couldn't find an issue, but then found the exact same fault. this was a known issues on some care that used the climate system up to revision 'L' where they had phased out the G89 temp sensor in the air inlet duct.

The other issue i had with mine is that the A/C pipe under the bonnet would frost up, and i mean freeze on the outside, which I thought was odd, the garage said that this was not unusual. However in all the other cars I've owned including Mk1 Cupra this has never happened, maybe a bit of condensation, but not frost.

It seems that the A/C stops working, and the fan does not blow out the air (even at max fan speed) with very much force.
I have to turn off the whole climate system completely, and then wait 10 mins, and then turn back on and it seems to work ok.

In the heat of the summer, the A/C would not push out cold air until after about 7-10mins of driving.

Did you get any more info on yours=, or even solve the issues?

Cheers

Jon

 

[Traction]

@Traction

Hello mate,

I'm having pretty much the same symptoms you've described in my MY07 Cupra.
My own diagnostic handheld unit picked up a G89 temp sensor fault, and i took the car in to a local specialist, who couldn't find an issue, but then found the exact same fault. this was a known issues on some care that used the climate system up to revision 'L' where they had phased out the G89 temp sensor in the air inlet duct.

The other issue i had with mine is that the A/C pipe under the bonnet would frost up, and i mean freeze on the outside, which I thought was odd, the garage said that this was not unusual. However in all the other cars I've owned including Mk1 Cupra this has never happened, maybe a bit of condensation, but not frost.

It seems that the A/C stops working, and the fan does not blow out the air (even at max fan speed) with very much force.
I have to turn off the whole climate system completely, and then wait 10 mins, and then turn back on and it seems to work ok.

In the heat of the summer, the A/C would not push out cold air until after about 7-10mins of driving.

Did you get any more info on yours=, or even solve the issues?

Cheers

Jon

Hi @jonny76

Good to know I'm not alone!

Not sure what revision my climate system is. All I know is that its a very early MK2 leon - 05 so I'm guessing the climate system is fairly old.

I haven't actually checked the A/C pipe but its the first year I remember seeing water under the car after using the air con.
Its always fairly quick to blow the cold air.
The re-gas was right at the end of the summer so couldn't really quantify the improvement.

Haven't done any more about it since. Didn't do too many long journeys since.
I must investigate the G89 temp sensor.
It does sound like the issue, because in the past I've had it heat and then stop too.
So temperature sensor sounds likely.
Was you G89 sensor replaced?


I have been told that there was a TPI about Air Conditioning not cooling - temporarily/permanently.
I think all the fixes were to do with the compressor, either replacing the compressor or the pulley.
But that only applied to certain Valeo or Zexel compressors.

I'll be sure to post any updates if I get them.