I have posted about this problem before but it remains unresolved. The car has been laid up for a while but I plan to use it again this summer.
It has an R12 system. Initially the aircon when switched on works and cools - but only down to an air temperature from the airvents of 9deg. So the initial cooling performance is a bit below par.
However the main problem is that after running for half an hour or so, depending on the external temperature the cooling stops altogether. The compressor though is running continually as if the evaporator is iced up. It is not. If I then park the car, in warm or hot temperatures for thirty to sixty minutes then when I drive off, the compressor is still on continually with no cooling at all. There is never any condensate dripping from the drain tube and it is not blocked.
There must be a logical explanation for this. Is it a combination of low refrigerant level and some kind of Tx valve malfunction or blockage combined with a pressure switch failure. Or just another BX playing up in an original way. What do you think guys ??
I did run the problem past my local aircon guy recently and he had no idea what it could be at all. Not that I expected any words of wisdom anyway.
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Jaba
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More aircon issues
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
Sound a bit like a short of gas job to me.
These systems "pump down" as it's referred to in the treade, meaning in laymens terms that the pressures get reduced as the temperature comes down and accumulate in the receiver.
Are you 100% certain the compressor is still spinning all the time when it does this though or is it cycling on the hp/lp switch?
I'd suggest that before you go any further, check to see if you have any leaks. This is done by painting a water and (app 10%) detergent mix around all the joints. Any bubbles and I mean ANY bubbles at all regardless of how few or how small indicates a leak. Also, check the sight glass on top of the receiver dryer and see if it starts up clear or cloudy and if it does clear, look carefully to see if it's due to the gas passing through sans air or if it is just no gas in the dryer.
To test, paint on all joints and closely inspect. If running, pay very close attention to anything on the discharge side. If not running pay attention to the suction side. Reason for this is that higher pressures exist on these sides at those times.
If a leak is found, then firstly try to tighten the joint until it stops. Look for any signs of oil stains which is an idication of a leak at any time.
If no signs can be found, replace all "O" rings, in fact, if the O rings are original, I'd be inclined to replace them anyway due to age. The old black rubber types are replaced by green poly ones these days as they are R134a compliant and last longer anyway.
If the receiver/dryer looks old, replace it. Again play it safe by getting an R134a compliant one (dessicant 9 IIRC) because this is where the bockage may exist. They have been known to have all the crystals break down inside which after a few minutes running get stirred up with the gas and oil and get lodged in the gauze internal filter.
If it were mine, I'd firstly see if I can find the leak as described as I'm not into this magic green dye caper these fellas play with as they seem to just fill the system with this crap instead of finding the leak. If none is found, I'd be getting the system emptied and replacing all the "O" rings and receiver dryer and then getting it charged with greenfreeze refrigerant.......then you'll see what really cold air feels like.
Alan S
These systems "pump down" as it's referred to in the treade, meaning in laymens terms that the pressures get reduced as the temperature comes down and accumulate in the receiver.
Are you 100% certain the compressor is still spinning all the time when it does this though or is it cycling on the hp/lp switch?
I'd suggest that before you go any further, check to see if you have any leaks. This is done by painting a water and (app 10%) detergent mix around all the joints. Any bubbles and I mean ANY bubbles at all regardless of how few or how small indicates a leak. Also, check the sight glass on top of the receiver dryer and see if it starts up clear or cloudy and if it does clear, look carefully to see if it's due to the gas passing through sans air or if it is just no gas in the dryer.
To test, paint on all joints and closely inspect. If running, pay very close attention to anything on the discharge side. If not running pay attention to the suction side. Reason for this is that higher pressures exist on these sides at those times.
If a leak is found, then firstly try to tighten the joint until it stops. Look for any signs of oil stains which is an idication of a leak at any time.
If no signs can be found, replace all "O" rings, in fact, if the O rings are original, I'd be inclined to replace them anyway due to age. The old black rubber types are replaced by green poly ones these days as they are R134a compliant and last longer anyway.
If the receiver/dryer looks old, replace it. Again play it safe by getting an R134a compliant one (dessicant 9 IIRC) because this is where the bockage may exist. They have been known to have all the crystals break down inside which after a few minutes running get stirred up with the gas and oil and get lodged in the gauze internal filter.
If it were mine, I'd firstly see if I can find the leak as described as I'm not into this magic green dye caper these fellas play with as they seem to just fill the system with this crap instead of finding the leak. If none is found, I'd be getting the system emptied and replacing all the "O" rings and receiver dryer and then getting it charged with greenfreeze refrigerant.......then you'll see what really cold air feels like.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.
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Jaba
- 1K Away
- Posts: 1897
- Joined: Tue Jul 05, 2005 7:54 am
- Location: Usually in the garage
- My Cars: BX GTi, C3 Auto
- x 82
That sounds like sensible advice Alan. The d/r is original - 17 years old now with no sight glass.
The compressor is definately spinning ALL the time when there is no cooling. The cycling on and off of the compressor does work as it should when starting from cold but only up to the time when the cooling fails. At which time there is presumably enough pressure to satisfy the l/p switch but no cooling and insufficient pressure to make the h/p switch kick in. I think you must be right about more gas being required.
Also the evaporator sensor might be defective as it should not open the circuit at 9deg.
The water + detergent gas leak test I am very familiar with having worked in the domestic gas industry for a while. I will give it a go in June when I am back in the UK.
The compressor is definately spinning ALL the time when there is no cooling. The cycling on and off of the compressor does work as it should when starting from cold but only up to the time when the cooling fails. At which time there is presumably enough pressure to satisfy the l/p switch but no cooling and insufficient pressure to make the h/p switch kick in. I think you must be right about more gas being required.
Also the evaporator sensor might be defective as it should not open the circuit at 9deg.
The water + detergent gas leak test I am very familiar with having worked in the domestic gas industry for a while. I will give it a go in June when I am back in the UK.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.