Cold air that stops but will recover after turning off for a while usually means under charged. Without enough charge the difference between high and low pressure is too high and the evaporator will get below freezing and freeze solid.

Easy diagnoses: turn off ac and drive 20 minutes. If comes back on strong after a pause it's likely low freon

I sure hope so. Don't feel like doing the AC compressor thing.


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Just checked with INPA. No errors on the hvac module.


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It's that time of year in SA huh? Had our first 90+ day the other day and noticed the AC would not cool well unless on the highway. Vent temp was ~80f. Brought her home, put the can of 134 on there and "topped" up the system. Vent temps vary due to conditions, but got it down to 48f while charging it and stopped there as I did not want to over-fill the system.


I'd suggest topping up your refrigerant first... it's cheap, and usually solves the issue. If you have to do it more than once or twice a summer, the leak should be put on a "to-do" list for upcoming repairs. That's how "I roll" anyway. :D

Did the exact same thing to my 4.6.
It needed just a few ounces to top off.
Blistering cold now.

AC Takes forever to blow cold.
 

There is a decent DIY 134a can with a house and a gauge: the gauge importantly has a dial you turn to adjust for ambient.

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This was when I charged my wife's E53. Ambient was brutal about 90F

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Sub 40°F output when 90 outside is ok. Her car actually got too cold and would freeze up the evaporator I think the low side was about 25# when I started.

Annoyingly the static pressure of a can of 134a is about 50# so it takes a while to get anything out of a can when you are charging at 45#. Very helpful to have the manifold with the high pressure to get a better picture.

When ambient of 70 or so will be easier to charge.

I charged her car shortly after acquired and we are just going into the third summer and it puts out cold air but I will check to make sure it's still charged lest we end up with a frozen evaporator again.

I'm afraid to do it myself and fukit up ☹️


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A simple recharge is usually about $100usd


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If you want some assistance... just shoot me a PM with your # and I'd be happy to get with you. Doesn't take more than half an hour, usually takes much less.


^Andrew is right though. A pro re-charge from somewhere like Carlisle's (best AC place in town) is usually around $100. They usually try to upsale the leak diagnosis but... upsaling is a part of every business. :dunno:

AC Takes forever to blow cold.
 

Should I do the leak diag tho.
I mean if it's low it's leaking from somewhere, right?

My M3 is older with more miles and the AC still works fine.


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