1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

AC air not cool enough

Turbo_Boss Nov 15, 2013

  1. Turbo_Boss

    Turbo_Boss New Member

    Hello Guys,

    Hope you can help me resolve my problem that I fill my AC air is not cool enough.

    Car is a 2002 A4 1.8T with Climatronic AC

    One month ago the air conditioner was no throwing cold air. I open the hood and the compressor magnetic pulley was engaging, so the system has gas. Took the car to a AC Tech that always has fix my other cars and he connect his refrigeration gauges and it was needing gas.

    I ask him why if the system need gas the compressor never stop working since I know it have a safety pressure valve. He toll me that it only need a small amount of gas. I am pretty sure when he hook the refrigeration gauges, I saw it was reading 40lbs and he toll me the system needs 45lbs.......... He put gas and the AC was cooling like when the car was new.

    Using the car during the next month, I was filing that the AC was gradually decreasing on cooling.

    Took the car again to the same AC Tech and he begin to check all the AC parts in the engine compartment in order to look for leak with oil residues. He check the Compressor area, front Condenser and all the rubber hoses and don't find any leak or oil residue.

    I leave the car since he was going to check the evaporator. Later he call me and toll me that he need to change the evaporator since it have a crack and it leaking there.

    Today I pick up the car and he replace the Evaporator, Dryer Bottle, some O rings, put compressor oil, make vacuum, fill the system with gas and put new foam to the flap doors that mix hot air with cold air. He show me pics of the new foam he put to the flap doors.

    I enter my car, start it and set the AC temperature in 22º (I always use it in 22º) and the air was not cold. I need to set the air in 19º or 18º to fill that the air is cold and I don't think the air is cold enough. So I complaint with him that the air is not cold enough. He hook again his refrigeration gauges and check it again and put some more gas and toll me to use the car for some days.

    I drive it to my house and it was raining and the outside temperature was 28º and I need to put the AC in 18º to fill some cold air. I park the car in the garage with the engine running and AC on and under the car I can see that water was coming out from the side were the evaporator it is.

    I think when the outside temperature will be hot with a sunny day the AC will not cold :-(

    My question is: What can be the problem that I need to put the AC temperature in 19 o 18 to get some cool air?

    When the first time I was filling that the AC was not cooling anymore, I open the hood and the compressor magnetic pulley was engaging, so the system has gas but there was not cool air. Do this mean something to you? because I saw that it have 40lbs and he put a little more and then the AC begin to cool.

    Can all these symptoms can be that the expansion valve need replacement?

    I really appreciated you time and help,


  2. TYphoon GB

    TYphoon GB Active Member

    The problem with refrigerants like R134a is that the pressure is no indication of the quantity of refrigerant in the system. Only an accurate charge weight works and the system is charge sensitive so can't be easily charged by 'ear' as a lot of old techs did.

    Should be 505gm +/- 25g

    I have yet to see a failed evaporator in any vehicle. The Condenser (heat exchanger on the front) is however a weak point on all modern vehicles.

    Having ripped out what seems to be most of your system I fear you have air in the lines which means poor cooling.

    Set the system to the LO (lowest setting) and then check the air coming out the vents on maximum fan speed. Should be 5 to 10 Deg C colder than the cabin.

    The operating pressures would be good to know so ask your 'expert'

    Standing Pressure (that for R134a will tell me if there is air in there) need the air temperature (cold engine)

    Here's a few readings
    20 Deg C = 4.67 bar G
    22 Deg C = 5.04 bar G
    24 Deg C = 5.42 bar G
    So if its 22 Deg C and not 5.04 its got air in it.

    The high side running pressure (and the air temperature)

    The low side running pressure (again at the same air temperature)

    Also ask for a VCDS/Vag Com scan. That will tell us if there is a sensor and / or flap error.

    Highly unlikely the expansion valve is faulty unless they introduced some dirt into the system when they ripped it all out.
    Last edited: Nov 17, 2013
  3. Turbo_Boss

    Turbo_Boss New Member

    Hey TYphoon

    THX for all you explication.

    I put the Climatronic on Self-Diagnostics and the only problem it has is: 04FA Recirculation Flap Servo Motor. This servo motor has been damage since long time ago and I disconnected in order that the flap door is closed and is always in recirculate.

    The car is still on the AC Tech. He call me on Saturday and toll me the problem is the compressor. So I hope tomorrow morning the car is fixed and cooling.

    I was thinking that from day one, the problem was the compressor and that he change the evaporator without been this the problem........ But after thinking and thinking, I remember seeing under my car were it usually drop water when the AC is cooling, there was like a oil stain in the same spot, were I park my car, so I think that the evaporator was leaking refrigerant and also leak some compressor oil................

    What I dont understand is how the compressor is bad if the first time he only put refrigerant and the AC was cooling for around a month. :roll:


  4. TYphoon GB

    TYphoon GB Active Member

    Suspect but looks like your close. He only has the condenser and the expansion valve to go now...
    Always recirculate is not suggested. Fills the car with moisture and stale air.
    Useful if your in a tear gas attack however... :)
    Compressor wear at 11 years is not unexpected. If you had a leaking evaporator did he show you the old one?
    If you getting compressor oil in the drain then that's a big hit for a broken evap..
    Try a 'black light' UV torch to see if the florescent dye shows up in the oil.
  5. Turbo_Boss

    Turbo_Boss New Member

    Well, Today I pick up my car and he put a new compressor and the AC is cooling :rock: I am happy again.


Share This Page