Time for AC re-gas?

[Trewithy]

I used a local taxi firm yesterday, the car that turned up was a 73 plate Corolla TS.  One thing I noticed was the air coming out of the vents was a lot cooler than my car.  The settings in the taxi were Lo and one bar on the fan speed, the air was coming out of the dash vents.  I tried the same settings in my Corolla today and the air is definitely not as cool as the taxi.  My Corolla will be 5 years old in December and I rarely have the AC off.  Could it be time for a re-gas?

[Paul john]

5 years is about right for a re-gas

[fred88]

I had a brand new Aygo the day while my Battery was being looked at and that was far colder than mine too.

[TonyHSD]

I think 5 years been little bit overdue. 
AC regas should do every 2-4 years depending on use. 
My car is million miles and years and the ac can freeze you alive if I choose low settings, it blows 4C° through central vents.  

[miks]

there is no logical reason to re-gas ever. The compound is stable and system is closed type. if you need it means your AC system has a leak.

[Red_Corolla]

I've never had to re-gas a car that hasn't been leaking. The wife's Fiat is  very close to 10 years of age and A/C works great without ever having had a recharge.

Just get the system pressure checked if you're concerned, and only recharge if it's too low. The latest generation of refrigerant is quite a bit more costly than the old R134.

I find the fast/normal/eco setting in the Corolla has a big effect on how cold it blows. And low fan speed will axiomatically result in lower temperature air coming off the evaporator, but not necessarily better cooling (because the quantity of cold air will also be low).

[Mooly]

3 hours ago, miks said:

The compound is stable and system is closed type. if you need it means your AC system has a leak.

Hybrid and EV A/C systems are not hermetically sealed afaik. That would mean continuous pipework with no hoses to the condenser and all joints welded/brazed with no couplings anywhere. Domestic fridges and freezers are hermetically sealed which is why they never normally lose any refrigerant even over decades of use.  

 

On 9/13/2024 at 6:54 PM, Trewithy said:

One thing I noticed was the air coming out of the vents was a lot cooler than my car.  The settings in the taxi were Lo and one bar on the fan speed, the air was coming out of the dash vents. 

Its counterintuitive but a low refrigerant level can also actually cause the evaporator to run too cold under some operating conditions. If the line from the evaporator back to the compressor is super cold/frosty then low charge is one possibility. 

[Mjolinor]

R134A does tend to leak a lot more than R12 ever did.

Propane works well, I have actually used it.***

***Do not take that as a recommendation. 🙂

 

[TonyHSD]

All cars AC system naturally lose some gas over time.
Many owners never had problems, others never kept their cars for too long or never noticed any AC reduced performance, which is the most common sign of system low on gas. 
When system gets low on gas, it is not only the gas amount been reduced, but also the oil. Your AC will continue to work until almost empty when the sensor will detect low pressure and will not start AC compressor anymore. You gonna lose your ac in the car. , this is one negative. 
On the other hand, low oil in anything it’s not a good thing.
Oil does important functions: lubricate, disperse heat and reduce friction, prevents corrosion.
 

From a closed system filled with 480gr of gas and 11 ml of oil, in 4 years time there were lost a 100gr or gas and 3-4 ml of oil. The ac was working without any significant reduction in performance, no extra compressor noise or anything. However I did re gas to keep maintaining the best performance  and extend the life of the system. Keep maintain and no need to repair. 👌

[Mjolinor]

The other thing to bear in mind is that the longer you leave it under performing the less likely it is to work right if you gas it.

Once the gas is gone the remaning oil starts to disappear and the system gets water in. It does not take long before you have to replace the condenser filter and topping up the oil is fine if you just add a bit but the proper way to do it involves draining the oil and putting the correct measured amount in. Oil amount is very important for longevity.

[Mooly]

2 hours ago, TonyHSD said:

From a closed system filled with 480gr of gas and 11 ml of oil, in 4 years time there were lost a 100gr or gas and 3-4 ml of oil. The ac was working without any significant reduction in performance, no extra compressor noise or anything. However I did re gas to keep maintaining the best performance  and extend the life of the system. Keep maintain and no need to repair.

That sounds similar to mine. It had lost around 30% of the refrigerant but that was over 55k miles and 5 or 6 years at least with 24/7 use of the A/C. Like yours, it was still working fine.    

[forkingabout]

A modern vehicle will have R1234YF refrigerate.

[Cyker]

Yup, which is monopolized by Honeywell which is why it costs so much.

I was hoping CO2 would become the replacement refrigerant since it's better than R134 and R1234 in all environmental metrics and isn't flammable like R1234 but that's what they went with...

 

[fred88]

Have to admit that I'm guilty of AirCon paranoia.

Like the OP I've been in other cars recently, one a 24 plate Aygo X, and the AirCon through the central vent was significantly colder than mine. Having said that, mine (in the Corolla) seems to work ok it terms of whether the car becomes comfortable or not, and I don't really think I'd want it blowing much colder than it does anyway. My previous car, a Passat, was similar, I'm wondering whether its me 🤔 or whether its like that by design?

Anyway I've decided I'll probably get mine re-gassed in Feb '25 when its goes in for its next service. Not ideal in terms of feeling the immediate benefit but better than a double visit!

[TonyHSD]

1 hour ago, fred88 said:

Have to admit that I'm guilty of AirCon paranoia.

Like the OP I've been in other cars recently, one a 24 plate Aygo X, and the AirCon through the central vent was significantly colder than mine. Having said that, mine (in the Corolla) seems to work ok it terms of whether the car becomes comfortable or not, and I don't really think I'd want it blowing much colder than it does anyway. My previous car, a Passat, was similar, I'm wondering whether its me 🤔 or whether its like that by design?

Anyway I've decided I'll probably get mine re-gassed in Feb '25 when its goes in for its next service. Not ideal in terms of feeling the immediate benefit but better than a double visit!

How old is your car? 
If less than 4 years old then no need to worry about, if over 4 years old then it’s a good time to regas.
The ac service it’s not just to have ice cold ac but as periodic maintenance to secure proper and long lasting air conditioning in your car. 
Better time of the year to do this procedure is spring or summer till autumn but try to avoid winter time when air temperature is below 15C°. 
Also before you go and do that check your hvac settings. Eco set ON, or air conditioning compressor reduced noise function can reduce ac system performance. These can be checked with Carista obd 2 adapter and their app. 

[fred88]

Thanks for your input Tony. 

Car is 2 1/2 years old, 3 years at the next service (Feb), maybe I'll wait until Spring!

Do they test for leaks at a regas?

[Red_Corolla]

5 minutes ago, fred88 said:

Thanks for your input Tony. 

Car is 2 1/2 years old, 3 years at the next service (Feb), maybe I'll wait until Spring!

Do they test for leaks at a regas?

The machine first pumps out the existing gas using a vacuum pump. Once your system is under vacuum, it checks it's ability to hold it, so there's your leak test. I haven't come across one that tests the system in it's normal state, i.e. under pressure, but things may have moved on now; it's a long time since I had it done. The vacuum test doesn't reveal every leak.

I might give in to popular opinion and treat my wife's car to a recharge next year, after it's 10th birthday.😊 Might even replace the original Battery while I'm at it, although the tester says it's still good at the moment.

[Mjolinor]

It is more usual to fill them with nitrogen under pressure when testing for leaks.

 

[southsider46]

If it ain't broke, don't fix it.

[Mjolinor]

The cheap and cheerful way is :

One of these: https://www.ebay.co.uk/itm/156409513967

A can of this : https://www.ebay.co.uk/itm/284957500461 (that is R134A)

Some heath robinson piping and bob's yer dad's brother.

 

 

[fred88]

I tested back in the summer with it on Lo and fan speed on 2 or 3, can't recall exactly. I hung a thermometer on the vent with the bulb in the flow. The temp crept down to 10 C after 4 or 5 minutes. Ambient was 21 C. That might not be broke but it's not as it should be is it?

[southsider46]

2 hours ago, Mjolinor said:

The cheap and cheerful way is :

One of these: https://www.ebay.co.uk/itm/156409513967

A can of this : https://www.ebay.co.uk/itm/284957500461 (that is R134A)

Some heath robinson piping and bob's yer dad's brother.

 

 

That's the wrong stuff for the car in question.

[TonyHSD]

4 hours ago, fred88 said:

I tested back in the summer with it on Lo and fan speed on 2 or 3, can't recall exactly. I hung a thermometer on the vent with the bulb in the flow. The temp crept down to 10 C after 4 or 5 minutes. Ambient was 21 C. That might not be broke but it's not as it should be is it?

Yes, it should be colder and close to 4C° 

AC regas best to be done on a machine in garage and for hybrids particularly needs to be a specialist equipment that can work with different type of oil that hybrids are using. You have also different gas and diy kits aren’t any good. The machine will test for leaks and then refill exact amount oil and gas and this is what keeps your system working properly for many years. It’s not about if not broken don’t fix it, you don’t fix anything here,,you are simply looking after your car and the AC system.
Same as periodic oil and filter change , timing belt changes , brake service, coolant change etc. 

[fred88]

It'll be done at the dealership, won't take any chances with Warranty. 

[fred88]

With my AC's level of performance do you think I should regas now or can I wait?