Gargling/sloshing sound coming from behind climate control

SummerallGuard04 · 12-14-2023, 02:58 PM

Hello all--

I noticed this morning that there is a gargling/sloshing sound coming from behind the climate control. I noticed it when I had turned the thermostat all the way up to 84 degrees and had the fan on the lowest speed. I've been researching this for the last hour and it sounds like this is a common issue amongst several BMW models/years. Most of my search has led me to believe that there is water trapped in the heater core.

I found this youtube video to try and "burb" the air out and wasn't sure if it was a good idea or not:

I should also note that all AC components work just fine and, as of now, I only notice this percolating-like noise when the thermostat is turned all the way up to 84 degrees. I ran my AC at 83 degrees and didn't notice it as much; dropped it down to 78 degrees and there was no noise.

TIA!

Conserve · 12-14-2023, 04:50 PM

I don't think bleeding coolant system at any time and not just when coolant change occurs will have adverse effect to the system. just make sure you follow the bleeding procedure.

AussieBob · 12-15-2023, 04:39 PM

Could be one or more of the heater control valves getting stuck, replacing the heater control valve eliminated any slushing sound I used to get. The rubber diapharms in the valves deteriorate and cause the valves to not shut or open properly causing poor flow of coolant into the heater core and coolant then slushing around in the heater cores. Even with the climate control turned off I could still hear slushing. I replaced the simple part and problem was fixed.

Conserve · 12-15-2023, 05:59 PM

^ +1. every time I come here learn something new.

https://f10.5post.com/forums/showthread.php?t=1861362

Johnkwick · 12-24-2023, 02:23 PM

It's usually a symptom of low refrigerant condition. You can check the pressure level and/or refrigerant amount by visiting A/C shop

I found mine leaked refrigerant and oil on both low and high pressure pipes which located near the radiator. The coupler from/to pipe/rubber on both lines were failing and leaking some oil through that.

You can easily tell by oily and black residue around the coupler. Try to clean it with degreaser first and rub your fingers around the coupler after driving with A/C on for minutes. See if you have oil around that (caution: high pressure pipe is super hot! Let it cool after driving)

I replaced mine with non standard solution offered by Denso authorized workshop and super happy with that

12-14-2023, 02:58 PM	#1
SummerallGuard04 Private First Class 84 Rep 114 Posts Drives: 2016 BMW 550i M Sport Join Date: Sep 2021 Location: Fort Mill, S.C. iTrader: (0)	Gargling/sloshing sound coming from behind climate control Hello all-- I noticed this morning that there is a gargling/sloshing sound coming from behind the climate control. I noticed it when I had turned the thermostat all the way up to 84 degrees and had the fan on the lowest speed. I've been researching this for the last hour and it sounds like this is a common issue amongst several BMW models/years. Most of my search has led me to believe that there is water trapped in the heater core. I found this youtube video to try and "burb" the air out and wasn't sure if it was a good idea or not: I should also note that all AC components work just fine and, as of now, I only notice this percolating-like noise when the thermostat is turned all the way up to 84 degrees. I ran my AC at 83 degrees and didn't notice it as much; dropped it down to 78 degrees and there was no noise. TIA! __________________ 2016 BMW 550i M Sport - Mineral Gray Metallic 2015 BMW X5 base - Jet Black 2011 BMW 335i - Alpine White
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12-14-2023, 04:50 PM	#2
Conserve Private First Class 186 Rep 127 Posts Drives: 1976 BMW 2002 & 2015 BMW535i Join Date: Sep 2023 Location: Ohio iTrader: (0)	I don't think bleeding coolant system at any time and not just when coolant change occurs will have adverse effect to the system. just make sure you follow the bleeding procedure.
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12-15-2023, 04:39 PM	#3
AussieBob Private 80 Rep 92 Posts Drives: 2010 F10 "M5" Join Date: Sep 2018 Location: Australia iTrader: (0)	Could be one or more of the heater control valves getting stuck, replacing the heater control valve eliminated any slushing sound I used to get. The rubber diapharms in the valves deteriorate and cause the valves to not shut or open properly causing poor flow of coolant into the heater core and coolant then slushing around in the heater cores. Even with the climate control turned off I could still hear slushing. I replaced the simple part and problem was fixed.
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12-15-2023, 05:59 PM	#4
Conserve Private First Class 186 Rep 127 Posts Drives: 1976 BMW 2002 & 2015 BMW535i Join Date: Sep 2023 Location: Ohio iTrader: (0)	^ +1. every time I come here learn something new. https://f10.5post.com/forums/showthread.php?t=1861362
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12-24-2023, 02:23 PM	#5
Johnkwick Private 24 Rep 94 Posts Drives: F10 LCI Join Date: Mar 2020 Location: Southern Nusa Dua, Bali iTrader: (0)	It's usually a symptom of low refrigerant condition. You can check the pressure level and/or refrigerant amount by visiting A/C shop I found mine leaked refrigerant and oil on both low and high pressure pipes which located near the radiator. The coupler from/to pipe/rubber on both lines were failing and leaking some oil through that. You can easily tell by oily and black residue around the coupler. Try to clean it with degreaser first and rub your fingers around the coupler after driving with A/C on for minutes. See if you have oil around that (caution: high pressure pipe is super hot! Let it cool after driving) I replaced mine with non standard solution offered by Denso authorized workshop and super happy with that
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