New A/C blows warm air at idle

[Ms Char]

Hello all!

I recently had my a/c replaced in my '87 325i. It's working fine except the air blows warmer when the engine is at idle. For example, when I'm stopped in traffice, which is quite often, as I do lot of on local streets. The guy at the heating/cooling shop says the condenser fan isn't kicking into high as it should. Has anyone else had this problem or know of someone who has? What was the recommended fix?

 

[Ms Char]

OK, my mechanic explained that the older BMWs used a much cooler freon. Newer cars use a freon that cycles at a much higher temperature. The fans in newer cars have 2 cycles; one setting when the car is in motion and another that kicks in at idle. My BMW does not have the two-cycle fan motor that would cycle up at idle to accommodate the hotter running freon.

Can someone tell me if there's an upgrade that can be performed on the existing fan to accommodate this hotter running freon?

While the car is in motion the cabin is nice and cool, sometimes too cool. But, as soon as the car stops and idles, the temperature slowly starts to increase until it feels like the a/c isn't running. The longer the car idles (like in heavy rush hour traffice, which is when I do most of my driving) the hotter the cabin becomes.

Somebody, anybody... HELP!

 

[Big Daddy]

I think that is normal in most all cars as no air is flowing through the condensor. My 98 M roadster is very cool running down the road, but stopped at a light the AC is less cooler due to no air flow. My 91 750il was the same.

 

[Doughnut]

The a/c blowing warm at idle is unacceptable.
These old cars rolled off the production line with an a/c gas called r-12, your car has more than likely been recharged with r-134a (think thats right) which from what I've been told is not as good for cooling but is better for the environment compared to r-12.

was your a/c compressor replaced with a new one when they fixed the system? Just as a test, have your car parked, turn the engine on and run the a/c *blows warm air like normal* Now, while still parked on the spot rev your engine to say 3000rpm for a little while, does the a/c still feel warm? if it goes cold again while revving expect a work a/c compressor.

This is just my thoughts, I want to see if my test works, so do try it!!

 

[Ms Char]

I agree. It's totally unacceptable!

You're absolutely correct about the a/c being refilled with r134a instead of the r-12. The r-134a refrigerant was "sort of" banned in the US. If you can get it, it extremely expensive to have installed.

Prior to the installation of the new components (compressor, condenser, dryer) the system was converted from r-134a to r-12.

I ran your test, and what you predicted happened, as expected. What does that mean? Is there anything I can do?

 

[Big Daddy]

No the r-12 was banned not the r-134, and all that is left is what has been "recovered", that is why it sells for about $29.00 per can when prior to the 96 ban it was about $2.99 a can. From Discount Refrigerants, "Production of R12 or CFC-12 was halted by the clean air act on January 1, 1996." Why would you convert from r-134 to r-12 now?

 

[Doughnut]

I agree. It's totally unacceptable!

You're absolutely correct about the a/c being refilled with r134a instead of the r-12. The r-134a refrigerant was "sort of" banned in the US. If you can get it, it extremely expensive to have installed.

Prior to the installation of the new components (compressor, condenser, dryer) the system was converted from r-134a to r-12.

I ran your test, and what you predicted happened, as expected. What does that mean? Is there anything I can do?

So my test works!
I would think that your piston seals within the "new" a/c compressor are worn and not making enough pressure at idle.

Are you sure the a/c compressor is new?

And big daddy, he says at the beginning of the post that he has had the system converted from r-12 to r-134a, I'm guessing that it's a typo latter on in the post.

 

[Ms Char]

Yes, the latter was a typo.

I was wondering if my compressor was really new, as well.

After we replaced the dryer, which had a hole the size of a quarter in it, my a/c worked wonderfully, but only for 2 days. I took it back to the mechanic who replace the dryer, and he said I needed a temperature switch that went inside the dryer. He said he didn't replace the old switch because it looked okay at the time thhe put the dryer in. But before he could install the switch all the freon had to be safely removed so he sent me back to the place where the a/c was charged. When I returned to the coolant shop, the mechanic there said all the coolant had leaked out through the broken seals (not unexpected in a car that's 21 maybe 22 years old).

I was then told to take it back to the repairman to see about getting the seals repaired. Now, it hadn't worked since I bought the car 3 years ago. So it seemed the best thing to do was to replace the compressor and condenser, since we had no way of knowing what else might be wrong, and the chances that fixing the seals might not work were pretty high. In the long run, I paid $1065 for everything, including the freon. I thought that was very reasonable.

What I don't understand is why it's not running as well as it did with the old parts, before the freon ran out? I still think putting in new parts was the way to go, but now I wonder if I haven't been taken addvantage of? How can this be "normal"?

Maybe I'll take it to a dealer. I'd like to think my mechanic is reliable and trustworthy - he has been in the past - but I now wonder about that, because of this incident.

What do you think I should do?

 

[Doughnut]

In your last post what you describe sounds as though you were sent around on a wild goose chase!

I'm not sure what you should do, though I'm sure if you do go to get the thing looked/worked on it is going to cost you many more $$$ on top of what you have already paid.

If you lived nearby I'd GIVE you my a/c compressor I have both a e30 one and e34 one off my m30 that i've got no interest in using.

IMO, A/C is something I can do without.