Air Con Problems

[Alan Tann]

When I bought my Lexus in December 2006, the air con was not working it had error 23 on the air con side if you put it in diagnostic mode.

It though I would wait until the summer to get it gassed.

I had it gassed and it lost the gas after three weeks, my mechanic traced the leak to the condenser which I had replaced.

I had it regased again and the air con worked for the rest of the summer, but has lost the gas in the winter and brought back error 23.

I took the car to Quickfit and had it regased today, here are the results:

Before Recharge Check:

Low pressure port reading (AC off) 0 Bar

High pressure port reading (AC off) 0 Bar

Ambient Temperature 16.4c

Centre vent temperature (AC on) 40.2c!!!

The port readings were the same as above with ac turned on.

They added 00.700KG of R134A and 0010ml of oil.

After Recharge check

Centre vent Temperature 7.1c

Low pressure port reading (AC on) 2 Bar

High pressure port reading (AC on) 10 Bar

Why was the centre vent temp so high before the regas? Was this part of the problem I had last year?

Is 7.1c a good temperature for the air con or just average?

As even in this weather it does not feel that cold in the car with it on.

Also if it helps the car feels completely different to drive with the air con on.

I have had other cars with car air con before a Jaguar Sovereign and it always felt the same to drive with it on or not.

Thanks for any help Alan.

[Leadfoot]

Hi Alan,

What year is your car? I had the regassing done on my 98 recently and that was very cold out of the vents, around 4 degrees according to the specs.

[Alan Tann]

Hi Alan,

What year is your car? I had the regassing done on my 98 recently and that was very cold out of the vents, around 4 degrees according to the specs.

My car is a MK2 94. Thanks Alan.

[Haylands]

Alan

Seven degrees is not very cold, three to four is about right when it has been on for a while and is down to temp.

Did Quickfit do a vacuum test on your system, to do the job properly they should put the machine into "suck" mode and draw out all the remaining gas and then leave the system in a vacuumed state for 15-20 mins to draw out any condensation in the system, it should then be recharged with the correct amount. 0.7 kg seems about right.

If there was absolutely none in the system to start with then Quickfit should have definitely done the vacuum check which will show leaks, as there is little chance that natural degassing would lead to all of the gas being lost.

I fear that you will lose the gas over a short period of time and there will be a leak in the system.

Do you know if they added any die to help trace a leak?

I think that these quickfit type places are too happy to just refill aircon and not do the job properly and tell you it has a leak because then you won't pay for a fill up and they lose money.

I would go back in a couple of days and ask them to test the pressure again to see if you are losing gas, if you are then ask them to add some die which will show up any leaks.

If they get funny at all ask them why they didn't do a vacuum test to check for leaks before taking your money.

Sorry to be so negative about this. I hope it gets sorted for you

Pete

[steve2006]

HI,

I've got to agree, I think the normal proceedure if a leak is suspected is to presurise the system with nitrogen plus a dye that will show up leaks under ultraviolet light.

Once repairs if required are done the system needs to be purged of any condensation before regassing with the correct type of refridgerant and compressor oil.

It's not very often I say this about kwik *hit but I took mine in last year for testing and they told me it was fine and not to waste my money as they could not guarantee an improvement after.

BTW the centre vent temp was 4 degrees celsius on testing.

[Alan Tann]

If it is losing the gas, where could it be losing the gas from? My Mechanic thought it was the condenser, which I had replaced.

This makes sense as I was losing quite a bit of coolant before this was replaced, after the replacement the coolant level remains normal.

The print out from Quickfit states that a leak test was carried out and not leak was detected.

Vacuum time was 20 mins.

Thanks for any advice Alan.

[Alan Tann]

If it is losing the gas, where could it be losing the gas from? My Mechanic thought it was the condenser, which I had replaced.

This makes sense as I was losing quite a bit of coolant before this was replaced, after the replacement the coolant level remains normal.

The print out from Quickfit states that a leak test was carried out and not leak was detected.

Vacuum time was 20 mins.

will turning on auto make it any colder?

what needs to be done to achieve 3-4c?

Thanks for any advice Alan.

[Haylands]

If it is losing the gas, where could it be losing the gas from? My Mechanic thought it was the condenser, which I had replaced.

This makes sense as I was losing quite a bit of coolant before this was replaced, after the replacement the coolant level remains normal.

The print out from Quickfit states that a leak test was carried out and not leak was detected.

Vacuum time was 20 mins.

Thanks for any advice Alan.

Alan

Well thats a bit weird then, aircon systems don't usually lose every bit of gas, if they vacuum tested it then hopefully you don't have a leak, have you had it switched off all winter, this is not a good idea as the oil falls to the bottom of everything and the rubber seals harden and start to leak, always a good idea to use it at least once a week to keep it going. The condenser has nothing to do with the engine coolant it is a totally different radiator and cools the gas in the aircon system. Can't explain why your coolant leak has gone, maybe your mechanic saw a lose hose or something.

As mentioned earlier if it does leak get them to add some die to the system and you will be able to find the leak easier, most aircon places also have a gas leak detector which will "sniff" out a leak...

Hope you keep cool

Pete

[Haylands]

will turning on auto make it any colder?

what needs to be done to achieve 3-4c?

Thanks for any advice Alan.

Sorry didn't see those two.... turning to auto will not make it colder, turning to recirculate will make it cooler as it is cooling the already cooled air in the car.

If they can't get it any colder then I would go to a proper air con specialist and get them to check your system, could be a poorly pump or an air temp sensor, or lots of other things, they are quite complicated.

Pete

[Alan Tann]

Thank you for your replies Hayland.

I'm afraid you were right, it has lost all of the gas already!

My mechanic is taking the car in next Wednesday to run a dye trace.

Hopefully he can find the source of the leak.

I will post next week with the results.

Alan.

[Alan Tann]

Car went in today to see if they could find the leak.

My mehnic thinks that is the rubber seal on the pipe that connects to the front of the condensor.

He ran the dye test and you can see it all over that join.

It is going in next Thursday to replace this.

Hopefully this will fix the problem, exspecialy with the weather we have been having this week.

One question, my car only has one electric cooling fan, on the lefthand side of the engine.

But a digaram I have of a 94 MK2 Lexus shows two cooling fans?

Do your Lexus's only have one cooling fan?

Thanks Alan.

[Alan Tann]

Car went in today to see if they could find the leak.

My mehnic thinks that is the rubber seal on the pipe that connects to the front of the condensor.

He ran the dye test and you can see it all over that join.

It is going in next Thursday to replace this.

Hopefully this will fix the problem, exspecialy with the weather we have been having this week.

One question, my car only has one electric cooling fan, on the lefthand side of the engine.

But a digaram I have of a 94 MK2 Lexus shows two cooling fans?

Do your Lexus's only have one cooling fan?

Thanks Alan.

It has been over a week now and the aircon is still working!

That must of been where the leak was.

It is too cold now though, I have to keep puting it on auto 16 or low 0.5.

[Haylands]

Car went in today to see if they could find the leak.

My mehnic thinks that is the rubber seal on the pipe that connects to the front of the condensor.

He ran the dye test and you can see it all over that join.

It is going in next Thursday to replace this.

Hopefully this will fix the problem, exspecialy with the weather we have been having this week.

One question, my car only has one electric cooling fan, on the lefthand side of the engine.

But a digaram I have of a 94 MK2 Lexus shows two cooling fans?

Do your Lexus's only have one cooling fan?

Thanks Alan.

It has been over a week now and the aircon is still working!

That must of been where the leak was.

It is too cold now though, I have to keep puting it on auto 16 or low 0.5.

Great news Alan, its nice when you finally get to the bottom of a problem.....

Stay coooooool

Pete

[Alan Tann]

O'dear the car has lost the gas again.

At least it lasted ten days this time.

My mechanic thinks the leak is begind the dash, as there is a strong smell of gas after using the aircon and turning it off.

Does anybody have any idea where to look behind the dash and how to remove it?

Thanks Alan.

[Nitmoi]

My ac techie in Saudi used soapy water on a brush on all the joints. If they bubbled they were leaking. No dye required. Very cheap and effective. Works on tyres, rims and valves too.

[thermoacc]

Hi Alan,

Probably a bit too late to give a reply to this topic, but as a a/c and refrigeration engineer it is my area of knowledge.

As nitmoi said above, pressurise the system and use a spray leak detector on all visible components. If no leaks are found using this method leave the system on a pressure test for a few hours to check the severity of the leak. If the system holds around 5Bar of nitrogen with little or no deviation it is therefore evident that it is a small leak and further work is required.

A small amount of R134a is added to the system and this is again pressurised with nitrogen up to around 5Bar as a starting point. An electronic refrigerant detector or "sniffer" is then passed over all components and pipework. These "sniffers" are very sensitive and can locate the smallest of leaks. When the sniffer beeps, the leak is found!....spray the area with leak detector and check for bubbles...if none are found, increase the pressure 2Bar at a time untill the bubbles are formed. This is how to exactly locate a leak. The easiest way to eliminate the evaporator (the component behind the dashboard) is to place a sniffer in one of the floor vents..if it gets a reading the evaporator is leaking...much quicker than taking a screwdriver to the dash and airbox..Especially on a Lexus!!!

After a leak is repaired the system must be pressure drop tested using dry nitrogen at around 8 to 10Bar for at least 24 hours to check that there are no further leaks present.

If all ok, the system is then given fresh oil (pending an acid test and quantity check) and it is always necessary to change the filter/dryer after any refrigeration system is opened or the system is open to atmosphere after a leak. The system is then evacuated of all air and moisture using a double stage vac pump in conjunction with a electronic vacumn guage untill under 500micron is achieved. Correct evacuation of the system is crucial and the time taken to achieve this reading (or better!) will ensure the best possible "air off" temperature at the vents.

The correct amount of refrigerant is then added as a liquid using an electronic weighing scales to the manufactures specifications and the system run.

Pressures are then taken as the system is run and refrigerant can then be added/removed to attain the correct operation conditions.

After all work is done, spray the access ports with leak detector to check the valves are correctly seated and are not passing and fix the screw caps back on checking that the o-rings are present and correct.

Phew!....if any further info on this type of work is required, you are more than welcome to contact me as the above is a very general overview.

Kwik Fit would never carry out work like this and the adverts saying "10% cooler or your money back" always make me smile!

[Haylands]

thermoacc, thanks for that, its good to have another knowledge base on here....

Kwickfits 10% cooler claim seems a bit funny to me as well, do they mean 10% of the difference between outside temperature and inside or 10% of the temp coming out of the vents.... i.e. 4 deg so 10% of 4 deg = 0.4 deg....

Pete

[thermoacc]

Hi Haylands,

You know, I am not sure about Kwik fit`s statement but 10% is a very poor goal considering they want you to part with cash to be 10%cooler! On a hot summers day (I wish!) 10% of 30degC is is not going to make you feel that much better!

Their practice in A/C repair days are numbered as changes in refrigerant law will stop them soon.

I see so many people on the internet with car a/c faults and shudder when I hear how much they have spent replacing condensers and the like....luckly, it is not much of an issue with a Lexus...the systems use very good quality components, like the rest of the car!

As for costs in general, a bottle of R134a is around £55 and is enough to "re-charge" around 20 cars!

[murphy jim]

Hi Alan,

Probably a bit too late to give a reply to this topic, but as a a/c and refrigeration engineer it is my area of knowledge.

As nitmoi said above, pressurise the system and use a spray leak detector on all visible components. If no leaks are found using this method leave the system on a pressure test for a few hours to check the severity of the leak. If the system holds around 5Bar of nitrogen with little or no deviation it is therefore evident that it is a small leak and further work is required.

A small amount of R134a is added to the system and this is again pressurised with nitrogen up to around 5Bar as a starting point. An electronic refrigerant detector or "sniffer" is then passed over all components and pipework. These "sniffers" are very sensitive and can locate the smallest of leaks. When the sniffer beeps, the leak is found!....spray the area with leak detector and check for bubbles...if none are found, increase the pressure 2Bar at a time untill the bubbles are formed. This is how to exactly locate a leak. The easiest way to eliminate the evaporator (the component behind the dashboard) is to place a sniffer in one of the floor vents..if it gets a reading the evaporator is leaking...much quicker than taking a screwdriver to the dash and airbox..Especially on a Lexus!!!

After a leak is repaired the system must be pressure drop tested using dry nitrogen at around 8 to 10Bar for at least 24 hours to check that there are no further leaks present.

If all ok, the system is then given fresh oil (pending an acid test and quantity check) and it is always necessary to change the filter/dryer after any refrigeration system is opened or the system is open to atmosphere after a leak. The system is then evacuated of all air and moisture using a double stage vac pump in conjunction with a electronic vacumn guage untill under 500micron is achieved. Correct evacuation of the system is crucial and the time taken to achieve this reading (or better!) will ensure the best possible "air off" temperature at the vents.

The correct amount of refrigerant is then added as a liquid using an electronic weighing scales to the manufactures specifications and the system run.

Pressures are then taken as the system is run and refrigerant can then be added/removed to attain the correct operation conditions.

After all work is done, spray the access ports with leak detector to check the valves are correctly seated and are not passing and fix the screw caps back on checking that the o-rings are present and correct.

Phew!....if any further info on this type of work is required, you are more than welcome to contact me as the above is a very general overview.

Kwik Fit would never carry out work like this and the adverts saying "10% cooler or your money back" always make me smile!

[murphy jim]

Hi thermoacc,

Whereabouts are you in South Wales?

Can I PM you?

[thermoacc]

Hi thermoacc,

Whereabouts are you in South Wales?

Can I PM you?

Hello there....

I live near Caerphilly in S.Wales.....If you have a A/C prob, I would be more than happy to help if can. PM anytime, I check in here around twice a week.

[daveyboy1]

Hi Alan,

Probably a bit too late to give a reply to this topic, but as a a/c and refrigeration engineer it is my area of knowledge.

As nitmoi said above, pressurise the system and use a spray leak detector on all visible components. If no leaks are found using this method leave the system on a pressure test for a few hours to check the severity of the leak. If the system holds around 5Bar of nitrogen with little or no deviation it is therefore evident that it is a small leak and further work is required.

A small amount of R134a is added to the system and this is again pressurised with nitrogen up to around 5Bar as a starting point. An electronic refrigerant detector or "sniffer" is then passed over all components and pipework. These "sniffers" are very sensitive and can locate the smallest of leaks. When the sniffer beeps, the leak is found!....spray the area with leak detector and check for bubbles...if none are found, increase the pressure 2Bar at a time untill the bubbles are formed. This is how to exactly locate a leak. The easiest way to eliminate the evaporator (the component behind the dashboard) is to place a sniffer in one of the floor vents..if it gets a reading the evaporator is leaking...much quicker than taking a screwdriver to the dash and airbox..Especially on a Lexus!!!

After a leak is repaired the system must be pressure drop tested using dry nitrogen at around 8 to 10Bar for at least 24 hours to check that there are no further leaks present.

If all ok, the system is then given fresh oil (pending an acid test and quantity check) and it is always necessary to change the filter/dryer after any refrigeration system is opened or the system is open to atmosphere after a leak. The system is then evacuated of all air and moisture using a double stage vac pump in conjunction with a electronic vacumn guage untill under 500micron is achieved. Correct evacuation of the system is crucial and the time taken to achieve this reading (or better!) will ensure the best possible "air off" temperature at the vents.

The correct amount of refrigerant is then added as a liquid using an electronic weighing scales to the manufactures specifications and the system run.

Pressures are then taken as the system is run and refrigerant can then be added/removed to attain the correct operation conditions.

After all work is done, spray the access ports with leak detector to check the valves are correctly seated and are not passing and fix the screw caps back on checking that the o-rings are present and correct.

Phew!....if any further info on this type of work is required, you are more than welcome to contact me as the above is a very general overview.

Kwik Fit would never carry out work like this and the adverts saying "10% cooler or your money back" always make me smile!

Hi, Iam probably on the wrong forum but you sound like a bit of an expert on these things, i have had my 05plate IS200 for a couple of weeks now , and as the nights are getting colder i have noticed that my car is misting up from the inside, when i park it up. virtually all the windows cover with condensation. This is obviously worrying, could it be an air con problem....iam totally mystified.