Air Conditioning Problem

A little off topic but ive always wondered why the A/C piping is not incorporated into the intercooler and pipe work as them pipes dont half get cold and would have a positive effect
 
wilco184 said:
I'm not entirely sure, but I've read that its possible to measure the HP and LP sides with the compressor running to ensure it's functioning correctly - hence the need for the two valves.

Regards,

Matt.
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The AC guys I visited definitely hooked up to both valves on the pipes with the compressor running to check pressure and function.
 
Thanks guys I figured it out but unfortunately I have a leak so in need of a new ac radiator/condensor
 
I just fitted a new condenser, bought it from AutoDoc in Germany for about 75€. You'll also need new o-rings for the hose fittings and I'd suggest you change the receiver dryer as well.
 
8E0 260 749 B, o-ring 11,1x1,8mm. Fits both upper and lower condenser connection.

There's also an o-ring on the pressure sender, but there's no separate part number for it. The size is roughly 8x1,8mm. You can probably reuse the old one, but mine split on removal and I had to replace it with an off-the-shelf o-ring.
 
Hi just a follow on to me reporting a similar drop in cold air from the climate - a re gas and all is chilly again - this also sorted vonnies out as well so possibly with both of our cars having stood unused for a few weeks it may have lost some gas as the seals dry out. So nice to have the freezer door open feeling back.
Cheers Mike
 
a2sumo said:
both of our cars having stood unused for a few weeks it may have lost some gas as the seals dry out.
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No Mike, the seals in an A/C system never see any liquid. The only part that does is the reservoir (this is often referred to as the dryer). Any liquid reaching the compressor would cause it to fail because you cannot compress a liquid. That's why it is important not to overfill the system. O-rings have two modes of failure: 1) Becoming too rigid because of low temperatures (as in the space shuttle Challenger) and 2) Being incompatible with the vapour/liquid that they are exposed to. 1) is not a problem because the A/C switches off at just above freezing and 2) the seals are selected to be compatible with the refrigerant. So if you are losing refrigerant, it's almost certainly due to a leak and the leak is most likely to be in the condenser, which by the nature of what is does, has the largest surface area of any A/C component and is the most lightly constructed.

Pressure is also not a good guide as to whether you have a leak. You might have a lot of liquid refrigerant in your system but this will not generate pressure. If you have a leak and very little liquid left, the pressure will be the same. Also, if you switch the A/C on, higher pressure will be generated and the leak rate will likely increase. However, if the system leaks at this higher pressure, it will also leak at the lower pressure with the A/C off, just slightly slower. So the idea that you should use the A/C to stop it leaking is just a myth!

Same for the compressor seal, as the compressor is always turning (assuming it hasn't failed) whether the A/C is on or off.

RAB
 
I stand corrected-thank you RAB. It would appear that our cars have just lost refrigerant from natural loss which can be unto 20%-the system was leak tested and evacuated of old gas/ lubricant. Still nice to get the cool factor back in our A2's. cheers mike
 
Hi I am new to a2s but have all ways liked the look, I have not long bought a tdi 90hp, mine has couple of issues with the air conditioning can anyone help when I turn on the air con clean water is sprayed in to the drive+passenger well I can't find where it comes from all so the blower speeds up and down on its own
 
Hi everyone thanks for the reply ,I have had my a2 computer scan they seem to think it is the blower motor or the control unit at fault that alters the speed of the motor has anyone had to change a control unit because of this problem, mh
 
Can you post faults there?

I changed heater motor blower resistor (which regulates motor speed) because blower motor was working by it self. Sometimes it worked, sometimes not.

It cost me 35 EUR for new resistor and some time.

IMG_0649.JPGIMG_0650.JPGIMG_0647.JPG
 
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Haven't posted here in a while, but now I'm running into some issues with my aircon and I can't figure out what's going on.
First things first. The aircon hasn't worked for a number of years. The car sat idle for a year, before which the aircon worked fine, and after that hasn't worked at all for the past two years. Had trouble locating parts and with the typical Scandinavian green winter (summer for you folks) the past few years I didn't really mind the lack of cool air.

Anyway...
I ran VCDS checks and had a defective G263 which I replaced. The High pressure sender appeared to be not working as it was indicating 1BAR even though the garage said I had good pressures so replaced that too, and now it reads pressures as it should.

I'm still not getting any cold air at all, not even cool air. The high pressure side of the AC appears to be low although it does increase from rest 5BAR to active 7BAR or so (this varies with ambient). So, I could have a bad compressor (likely) or blocked system (?) or could the system have run out of fluid somehow?
The thing I can't figure out is why I'm not getting even a smidgen of cool air through the evaporator. The high pressure line is COLD after the expansion valve and causes condensation, but it appears that any cooling effect is lost in the evaporator, or ducts.

There are no faults in the system according to VCDS. The Temperature Flap Potentiometer appears to run from high to low end when going from LO to HI on the climate control. It also produces heat as it should.

Could the temperature flap stop in an intermediate position? Is it possible to recalibrate the temp flap motor and positions?
I'm curious to know just how cold the high pressure line needs to be for there to be a noticeable cooling of the air from the evap.

Any ideas are welcome.
/Krister
 
when you run 001 in the HVAC on VCDS, what happens? It should cycle all the flaps through, you can read the values goinig from 0 to 255 or so and back again.

What are the values for blocks 001, 007 and 008?

- Bret
 
If the flaps are OK, check the compressor by removing the auxiliary belt. Check that the compressor turns with the pulley; if not, it means that safety "clutch" (which protects the aux. belt) has failed between the two and a new compressor is required. Mark the direction of travel of the belt before removal.

RAB
 
Thanks for replies.

RAB, it's a variable displacement compressor on the 1.4 Petrol, so no clutch. Compressor turns as it should and it does increase pressure in the system, just not as much as one would expect.

Bret:
001 readings with Climate Control in "AUTO" typically; 0.800 Amps, 75-90% (varies), 25-30%, 7-10 BAR (varies with ambient temp).
If I switch to ECON, it reads; 0, 0, 25% and usually 2 BAR less than when in auto, so 5-8 BAR.

007 readings vary with ambient of course, but Typically; 30, 30, 24, 30. I managed to get a reading when it was a bit cooler the other night and it read; 24, 24, 22, 22. I was worried that my replaced thermocouple wasn't working but I think it limits at 24 degrees from the evaporator temp as it normally should read around 3 degrees...

008 readings are a few degrees less than 007.

Thanks,
Krister
 
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