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Discussion Starter #1
The a/c on my 01' 530 blows cool but not cold. The compressor is running. It seem like the air is cooler on the driver's side; there's definately some cooling happening. This comes on the heals of a blower that quit working. I replaced the resistor/regulator and the blower now works. The exterior temp. sensor is working, the temps on the controller are set at 60, and the center wheel is set at 3 blue dots. Any ideas???
 

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You may have a failed heater control valve. They are designed to fail in an open position, so you will have heat.

Another possibility is an air flap not closing off the heat.
 

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Bimmerdex 7.4!
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The most common cause of reduced cooling is the normal seepage loss of refrigerant. Your system may need to be professionally recharged.
 

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Certainly possible, but these systems seem to be quite tight: I have owned my car since '01, I've never had it recharged, and it still blows cold. Even if it had been charged during its previous life, it's still been at least 9 years.

There have been a couple of cases where the lack of cool has been traced to other failures in the system, rather than refrigerant, per se.
 

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The best thing you can do right now is to buy the a pocket temp gauge for $5 (local autoparts store).
Insert it in the car and take reading with car under a tree (shade).
Follow instructions on the package but I believe if temp output at the vent is 55F +/- 5F then you are OK (I am going from memory here).

Then READ this thread by Fudman:
http://www.bimmerfest.com/forums/showthread.php?t=452953
 

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Bimmerdex 7.4!
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The best thing you can do right now is to buy the a pocket temp gauge for $5 (local autoparts store).
Insert it in the car and take reading with car under a tree (shade).
Follow instructions on the package but I believe if temp output at the vent is 55F +/- 5F then you are OK (I am going from memory here).

Then READ this thread by Fudman:
http://www.bimmerfest.com/forums/showthread.php?t=452953
In the shade, with ambient temp below 75 and relative humidity below 60% the air out of the vents should be 34 or less. Take that to the bank
 

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Bimmerdex 7.4!
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Certainly possible, but these systems seem to be quite tight: I have owned my car since '01, I've never had it recharged, and it still blows cold. Even if it had been charged during its previous life, it's still been at least 9 years.

There have been a couple of cases where the lack of cool has been traced to other failures in the system, rather than refrigerant, per se.
You are correct, there are many possible causes of low cooling, but the most common on any 134a system over 7 years old is low refrigerant charge. By far.
The OP needs to check his low side (suction line) pressure. If the compressor clutch is kicking out at anything below 20 psi -and it is not blowing cold air!- then he will need it professionally recharged.
 

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Here you go from the mfg of the diagnostic tools:
http://www.id-usa.com/pdf/inst/GTH-2CS.pdf

INSTRUCTIONS / AUTO AIR CONDITIONERS:
1. Park car in shade when checking temperature.
2. Start engine and allow to run at a fast idle.
3. Turn air conditioner to maximum cool.
4. Insert probe, full length, in center outlet duct or right hand
outlet duct.
5. Allow approximately 5 minutes for accurate reading.
6. Readings of 45F to 60F indicate a properly charged system.
In-car ambient temperature of 75F to 85F should produce
duct temperatures of approximately 45F. Higher in-car
temperatures should increase duct temperatures to no higher
than 60o.
 

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Discussion Starter #9
Thanks for the feedback! I checked everything electrically and it was all good. Turns out that all it needed was a shot of freon. It works perfectly now. The indy that does some of the work on my E39s said that it is not uncommon for these cars to have a very small leak in their systems and that in a lot of cases, it's virtually impossible to pinpoint where it is. I my case the a/c has never needed to be serviced; thats in 9 years. Topping off the freon did the trick. The technician also said that it didn't need very much. Cost - $53.00, gotta love it; it could have been a whole lot worse. Thanks again for the feedback!
 

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You may have a failed heater control valve. They are designed to fail in an open position, so you will have heat.

Another possibility is an air flap not closing off the heat.
Is there any way to access this valve or the flaps without taking the dash apart?
 

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My friend told me something 20 years ago the simple thing to do with the A/C before you have a leak turn on the A/C between January and February for 10 min.
 

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resident, old fart
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The most common cause of reduced cooling is the normal seepage loss of refrigerant. Your system may need to be professionally recharged.
Don't really want to start another AC argument, but there is absolutely no such thing. This statement, as pertains to a BMW, is totally false. :thumbdwn:
 
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