AC is bad during hot day

tswperfect · 08-21-2015, 04:05 PM

Hi, all. Noticed that the strength of my AC depends on the temp outside. I drove the car last week in a 95F day, the ac was so bad and basically just blowing warm air. It was a totally nightmare.

But if the temp is 75F, I can feel cold air from AC. Is there something wrong with the AC system? How to diagnose the problem?

mr.fabulous · 08-21-2015, 05:58 PM

I would suggest the system is under-charged.

RoundelM3 · 08-22-2015, 08:15 AM

It's either low on refrigerant or has too much - both will produce the same symptom of not producing cold air. The AC in my wife's 128i will freeze you out of the car in 100-degree weather. Either take it to a dealer or a qualified independent shop and have them run a few simple tests, the first of which will be to connect a set of A/C gauges to check your high- and low-side pressures. From there, they can determine if it's as simple as adding/removing refrigerant or if there's a leak in the system or a component failure. Google is a good source of how automotive air conditioning works and what can fail that will produce your symptoms.

blue135 · 08-23-2015, 11:34 AM

Keep in mind that a/c systems (mobile or stationary) are designed for temperature differential, not temperature. So ambient temperature, exterior or interior color all have an effect. As does refrigerant level.

Xaoc · 08-24-2015, 09:00 AM

I've notice something similar on my car as well. I think it's still generating cold air (when I put my hand over the vent, I feel cold air), but maybe some of the fans arent circulating the air out of the A/C unit.

mrvco · 08-24-2015, 11:10 PM

Did you push the Max button?

Xaoc · 08-25-2015, 11:53 AM

Quote:

Originally Posted by mrvco

Did you push the Max button?

I have, yes. It was the only way to get any sort of cool air moving.

mistawall · 08-26-2015, 10:06 AM

i have/had the same issue. no cold air during the day but at night BRRRturned out i have a small leak in my AC system. did a recharge and its now cold as ice

08-21-2015, 04:05 PM	#1
tswperfect New Member 4 Rep 19 Posts Drives: VW Join Date: Apr 2015 Location: Cali iTrader: (0)	AC is bad during hot day Hi, all. Noticed that the strength of my AC depends on the temp outside. I drove the car last week in a 95F day, the ac was so bad and basically just blowing warm air. It was a totally nightmare. But if the temp is 75F, I can feel cold air from AC. Is there something wrong with the AC system? How to diagnose the problem?
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08-21-2015, 05:58 PM	#2
mr.fabulous Captain 209 Rep 893 Posts Drives: Women Crazy Join Date: Dec 2014 Location: Florida Gulf Coast iTrader: (0)	I would suggest the system is under-charged. __________________ 2011 135i MSport 6MT AW/black, 72Kmiles, bone stock, moneymoneymoneymoneymoneymoneymoneymoneymoneymoney I LOVE THIS CAR
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08-22-2015, 08:15 AM	#3
RoundelM3 Major General 1837 Rep 6,990 Posts Drives: 15 F80 M3, 22 G01 X3 30i Join Date: Apr 2010 Location: Clayton, NC iTrader: (2) Garage List 2022 BMW X3 [9.83] 2015 BMW M3 [6.50]	It's either low on refrigerant or has too much - both will produce the same symptom of not producing cold air. The AC in my wife's 128i will freeze you out of the car in 100-degree weather. Either take it to a dealer or a qualified independent shop and have them run a few simple tests, the first of which will be to connect a set of A/C gauges to check your high- and low-side pressures. From there, they can determine if it's as simple as adding/removing refrigerant or if there's a leak in the system or a component failure. Google is a good source of how automotive air conditioning works and what can fail that will produce your symptoms. __________________ 2015 F80 ///M3 Sedan 7DCT Tanzanite, 2022 X3 sDrive30i 8AT Brooklyn Grey
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08-23-2015, 11:34 AM	#4
blue135 Captain 374 Rep 652 Posts Drives: 2008 135i Convertible Join Date: Aug 2015 Location: Sarasota, FL iTrader: (1)	Keep in mind that a/c systems (mobile or stationary) are designed for temperature differential, not temperature. So ambient temperature, exterior or interior color all have an effect. As does refrigerant level.
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08-24-2015, 09:00 AM	#5
Xaoc Private 14 Rep 65 Posts Drives: LeMans Blue 135is Join Date: Jun 2013 Location: Chicago, IL iTrader: (0)	I've notice something similar on my car as well. I think it's still generating cold air (when I put my hand over the vent, I feel cold air), but maybe some of the fans arent circulating the air out of the A/C unit.
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08-24-2015, 11:10 PM	#6
mrvco Private 3 Rep 81 Posts Drives: 128i Join Date: Dec 2014 Location: Colorado iTrader: (0) Garage List 2008 BMW 128i [0.00]	Did you push the Max button? __________________ Year One of the One, N.A. Montego Blue/Coral Red, 6MT Sp/Pr/Wi/Xe
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08-26-2015, 10:06 AM	#8
mistawall Lieutenant 113 Rep 499 Posts Drives: 08 135i 6MT Join Date: Feb 2014 Location: ct iTrader: (1) Garage List 2008 BMW 135i [9.50]	i have/had the same issue. no cold air during the day but at night BRRRturned out i have a small leak in my AC system. did a recharge and its now cold as ice __________________ 08 135i\|1M conversion\|Montego Blue\|TFT Inlets\|Riss Racing DPs\|Riss Racing Exhaust\|Tial BOV\|VRSF 7"FMIC\|WEDGE TUNED\|BMS Short Throw Shift\|BlackLines\|PURE stg2\| follow me on instagram!
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