Slushy AC sound?

Jacob_f10 · 05-24-2021, 08:51 PM

Hello again everyone,

Getting a weird slushy sound when my AC is turned on. I think it's been there since I've owned the car, I'm just now noticing it more. Sound is coming directly from the middle vents, is this normal or should I be looking into something? AC works perfectly other than that weird sound which comes and goes.

SWFLf10 · 05-24-2021, 09:13 PM

Quote:

Originally Posted by Jacob_f10

Hello again everyone,

Getting a weird slushy sound when my AC is turned on. I think it's been there since I've owned the car, I'm just now noticing it more. Sound is coming directly from the middle vents, is this normal or should I be looking into something? AC works perfectly other than that weird sound which comes and goes.

I believe I hear the same thing. Heard it since I bought it. I've noticed that if the AC is set to the lowest temperature (60 degrees) the sound goes away. I'm not an AC technician, but my thought is that if it's not cooling 100%, then there is some valve that lets the coolant bypass slightly and that's the sound we are hearing.

spielnicht · 05-25-2021, 06:39 AM

Hummm, that sounds like a coolant system that's filled with air pockets and hasn't been bled properly. Coolant flows through the heater core and makes that slushy noise when the system is filled with air pockets.

Check your coolant/anti-freeze level, fill if low, then perform the auto bleeding procedure for the F10. Pretty easy to do. You might need to repeat the process a couple of times before the system is completely clear of air pockets.

Surly73 · 05-26-2021, 10:31 AM

If by AC you mean the "air conditioning" system activated by the snowflake - you may want to investigate if you have a low refrigerant situation. Some hissing can be normal as liquid refrigerant passes through the expansion valve. Gurgling is not normal. Earlier F10s are prone to weld failures on the AC condensor which allows refrigerant to escape. All cars are subject to slow loss and "crap happens" events.

If by AC you mean "the heating and cooling system" and not specifically the snowflake, it could be engine cooling making a trickling, waterfall like noise as it passes around the system and through the heater core. Check coolant level in the expansion tank and run the bleed program to see if that helps.

Cvx5832 · 05-26-2021, 01:50 PM

Quote:

Originally Posted by Surly73

If by AC you mean the "air conditioning" system activated by the snowflake - you may want to investigate if you have a low refrigerant situation.

This. If you're getting the hissing when request temp is right around ambient, the refrigerant is low. This is my experience with our F10, W212 and E46.

GrabacrOne · 06-07-2021, 06:58 PM

Quote:

Originally Posted by Jacob_f10

Hello again everyone,

Getting a weird slushy sound when my AC is turned on. I think it's been there since I've owned the car, I'm just now noticing it more. Sound is coming directly from the middle vents, is this normal or should I be looking into something? AC works perfectly other than that weird sound which comes and goes.

I think my car is making the same sound as yours. I've had this problem for the past few years but I'm not sure if it started only after a certain repair or service. I get this sloshing-type sound only when the A/C compressor is on (A/C or snowflake button pressed). It is easier to hear this through the center vents when the fan speed is set to low, i.e. 1 bar AUTO at 60 F. I only get the noise when there is load on the compressor (when temperatures are warm enough to require cooling). The thing is, the system always performs fine and keeps the cabin cool.

I was not sure if this was due to HVAC or engine coolant system. During a recent service, I had a new dealer check this and they found the A/C refrigerant to be very low this time. They recharged the system and noise was basically gone for a few hours of driving, then slowly returned, although not as strong as before. They placed a dye in the A/C system to check for leaks but when I took it back after a few weeks, they couldn't find any leaks and the system was still full. This confuses me - how could a pressurized system be "very low"? This would imply that there is a leak somewhere. Since the noise comes back, it seems like there is a slow leak. I had my A/C condensor replaced back in 2017 due to a complete loss of refrigerant.

Also, here are a few videos of the noise as well. The first video has it pretty clearly:

The second video is a bit longer and you’ll hear the noise periodically cycle on and off:

The volume may need to be turned up to high to hear the sound depending on your speakers. Let me know if this is what you're hearing.

dbs600 · 06-11-2021, 12:49 PM

Hi everyone.

I'd like to follow this thread, as I seem to be having the same problem.

Those of you who have the issue, can you please view and listen the following thread from another board:

https://www.bimmerfest.com/threads/g...vac-on.877328/

And from the videos posted, can you please confirm whether or not you are experiencing the same?

Thanks so much.

Very frustrating problem. :|

dbs600 · 06-11-2021, 12:51 PM

And anyone find any solution to this problem?

Taken your vehicles to your dealers?

If so, what have they said?

My best.

dbs600 · 06-17-2021, 10:39 AM

Hi everyone,

Hope all is well.

Wanted to check in to see if any updates.

For those of you with the problem, does the sound / noise match up with that of my videos?

Thank you.

My best.

Jacob_f10 · 06-17-2021, 10:43 AM

Quote:

Originally Posted by dbs600

Hi everyone,

Hope all is well.

Wanted to check in to see if any updates.

For those of you with the problem, does the sound / noise match up with that of my videos?

Thank you.

My best.

The video sounds exactly the same as mine, I haven't tried anything, or taken it into the dealer to ask (it's 200 bucks per diagnosis so it isn't worth it for me right now). My car also got dinged up by a bear so I have some other things to take care of before getting to the AC problem

I can give my service manager a call and see what he says. He's a cool guy and knows his cars so he might have some insight.

GrabacrOne · 06-18-2021, 01:29 AM

I had taken my car in to be diagnosed by my dealer since the noise had been driving me crazy. The shop foreman agreed that this sound wasn't normal, and sounded like low refrigerant in the system. The refrigerant levels were "pretty low" even though I had it recharged about a year ago. They added dye to the A/C refrigerant and checked the system for leaks after about a month.

Unfortunately, there were no leaks found, including in the evaporator and surrounding lines. The foreman raised the technical issue with BMW NA and their response was this is a normal noise for the F10 platform and the system is functioning properly. After testing a 2012 535i, the foreman found it to be exhibiting the same hissing noise. BMW NA's response was that this is a normal phenomenon when you have "refrigerant expanding through a low-mass evaporator coil, less than 12 inches from the center vents."

This noise only comes on when the system is running in a "maintain-temperature" mode, i.e., once the cabin has been cooled and the system is running at the lowest intensity just to maintain the target temperature. It happens whenever I come to a stop or drive at low RPM.

At this point, with BMW NA saying this is normal, there is not much more the dealer is willing to do. If the refrigerant levels drop low again, hopefully any slow leaks will be more detectable with the added dye. Maybe it is just something I have to live with

Surly73 · 06-18-2021, 07:41 AM

Hiss is not abnormal. Every car I've had hisses in some conditions. An operating AC system is like an aerosol can continually spraying in the evaporator. Some posters here are describing noises you can hardly hear (no radio, fan on low, stopped, idling, no traffic passing by, and the mic still barely picks it up). This is basically "looking for a problem" and potentially not understanding how air conditioning works.

Gurgling or sputtering can be a little different. This indicates that the high pressure side of the system is not full of liquid as it should be and there are pockets of gas in the liquid line. This can indicate a low refrigerant charge situation.

F10 owners have also described a "water fall" trickling sound. This usually ends up being low coolant (i.e. antifreeze, not refrigerant) or air in the cooling system and hearing it does not require the air conditioning (snowflake) to be on, but is accentuated with coolant is flowing through the heater core.

Losing refrigerant slowly (over the course of several years) is normal/allowable but needing a recharge annually is not. Chasing a leak you can't find must be very frustrating.

BITELCHUS_1980 · 07-31-2022, 03:43 AM

Quote:

Originally Posted by GrabacrOne

I had taken my car in to be diagnosed by my dealer since the noise had been driving me crazy. The shop foreman agreed that this sound wasn't normal, and sounded like low refrigerant in the system. The refrigerant levels were "pretty low" even though I had it recharged about a year ago. They added dye to the A/C refrigerant and checked the system for leaks after about a month.

Unfortunately, there were no leaks found, including in the evaporator and surrounding lines. The foreman raised the technical issue with BMW NA and their response was this is a normal noise for the F10 platform and the system is functioning properly. After testing a 2012 535i, the foreman found it to be exhibiting the same hissing noise. BMW NA's response was that this is a normal phenomenon when you have "refrigerant expanding through a low-mass evaporator coil, less than 12 inches from the center vents."

This noise only comes on when the system is running in a "maintain-temperature" mode, i.e., once the cabin has been cooled and the system is running at the lowest intensity just to maintain the target temperature. It happens whenever I come to a stop or drive at low RPM.

At this point, with BMW NA saying this is normal, there is not much more the dealer is willing to do. If the refrigerant levels drop low again, hopefully any slow leaks will be more detectable with the added dye. Maybe it is just something I have to live with

Good afternoon friend,

I am writing to you from Spain because I also have the same problem in my BMW F30, and it is driving me crazy. No one gives me a solution or they don't want to give it to me... Did you ever manage to solve yours? or at least know where the problem comes from?

Thank you very much and sorry for the inconvenience.

Thank you and regards

05-24-2021, 08:51 PM	#1
Jacob_f10 Private 12 Rep 59 Posts Drives: 2014 BMW 550i Join Date: Jun 2014 Location: California iTrader: (0)	Slushy AC sound? Hello again everyone, Getting a weird slushy sound when my AC is turned on. I think it's been there since I've owned the car, I'm just now noticing it more. Sound is coming directly from the middle vents, is this normal or should I be looking into something? AC works perfectly other than that weird sound which comes and goes. __________________ 550i-Model Year:2014-Build Date:July,2013-Engine: N63TU
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05-25-2021, 06:39 AM	#3
spielnicht Petrolhead 440 Rep 807 Posts Drives: 24 X3 M40i/14 550i/08 Z4 3.0si Join Date: Apr 2017 Location: Virginia iTrader: (3) Garage List 2008 BMW Z4 3.0si [9.67] 2014 BMW 550i [6.00] 2024 BMW X3 M40i [9.25]	Hummm, that sounds like a coolant system that's filled with air pockets and hasn't been bled properly. Coolant flows through the heater core and makes that slushy noise when the system is filled with air pockets. Check your coolant/anti-freeze level, fill if low, then perform the auto bleeding procedure for the F10. Pretty easy to do. You might need to repeat the process a couple of times before the system is completely clear of air pockets. __________________ . 2024 X3 M40i 2014 550i 2008 Z4 3.0si 6MT 2011 Z4 35si (sold)
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05-26-2021, 10:31 AM	#4
Surly73 Lieutenant Colonel 535 Rep 1,873 Posts Drives: '11 535xi 8AT KWv3 MPE MHD xHP Join Date: May 2012 Location: Oakville, Ontario iTrader: (1)	If by AC you mean the "air conditioning" system activated by the snowflake - you may want to investigate if you have a low refrigerant situation. Some hissing can be normal as liquid refrigerant passes through the expansion valve. Gurgling is not normal. Earlier F10s are prone to weld failures on the AC condensor which allows refrigerant to escape. All cars are subject to slow loss and "crap happens" events. If by AC you mean "the heating and cooling system" and not specifically the snowflake, it could be engine cooling making a trickling, waterfall like noise as it passes around the system and through the heater core. Check coolant level in the expansion tank and run the bleed program to see if that helps.
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06-11-2021, 12:49 PM	#7
dbs600 Colonel 269 Rep 2,246 Posts Drives: 2011 750LXi Individual Join Date: Apr 2010 Location: New York, NY iTrader: (0)	Hi everyone. I'd like to follow this thread, as I seem to be having the same problem. Those of you who have the issue, can you please view and listen the following thread from another board: https://www.bimmerfest.com/threads/g...vac-on.877328/ And from the videos posted, can you please confirm whether or not you are experiencing the same? Thanks so much. Very frustrating problem. :\|
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06-11-2021, 12:51 PM	#8
dbs600 Colonel 269 Rep 2,246 Posts Drives: 2011 750LXi Individual Join Date: Apr 2010 Location: New York, NY iTrader: (0)	And anyone find any solution to this problem? Taken your vehicles to your dealers? If so, what have they said? My best.
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06-17-2021, 10:39 AM	#9
dbs600 Colonel 269 Rep 2,246 Posts Drives: 2011 750LXi Individual Join Date: Apr 2010 Location: New York, NY iTrader: (0)	Hi everyone, Hope all is well. Wanted to check in to see if any updates. For those of you with the problem, does the sound / noise match up with that of my videos? Thank you. My best.
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06-18-2021, 01:29 AM	#11
GrabacrOne Second Lieutenant 178 Rep 274 Posts Drives: F10 535i Join Date: May 2013 Location: CT iTrader: (1)	I had taken my car in to be diagnosed by my dealer since the noise had been driving me crazy. The shop foreman agreed that this sound wasn't normal, and sounded like low refrigerant in the system. The refrigerant levels were "pretty low" even though I had it recharged about a year ago. They added dye to the A/C refrigerant and checked the system for leaks after about a month. Unfortunately, there were no leaks found, including in the evaporator and surrounding lines. The foreman raised the technical issue with BMW NA and their response was this is a normal noise for the F10 platform and the system is functioning properly. After testing a 2012 535i, the foreman found it to be exhibiting the same hissing noise. BMW NA's response was that this is a normal phenomenon when you have "refrigerant expanding through a low-mass evaporator coil, less than 12 inches from the center vents." This noise only comes on when the system is running in a "maintain-temperature" mode, i.e., once the cabin has been cooled and the system is running at the lowest intensity just to maintain the target temperature. It happens whenever I come to a stop or drive at low RPM. At this point, with BMW NA saying this is normal, there is not much more the dealer is willing to do. If the refrigerant levels drop low again, hopefully any slow leaks will be more detectable with the added dye. Maybe it is just something I have to live with __________________ Become a BMW CCA member! Click HERE to join and feel free to use my BMW CCA member #578262 as a referral. F10 535i M-Sport \| Gone but not forgotten: G01 X3 xDrive30i M-Sport; F15 X5 xDrive35i; E70 X5 4.8i Last edited by GrabacrOne; 06-18-2021 at 01:34 AM..
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06-18-2021, 07:41 AM	#12
Surly73 Lieutenant Colonel 535 Rep 1,873 Posts Drives: '11 535xi 8AT KWv3 MPE MHD xHP Join Date: May 2012 Location: Oakville, Ontario iTrader: (1)	Hiss is not abnormal. Every car I've had hisses in some conditions. An operating AC system is like an aerosol can continually spraying in the evaporator. Some posters here are describing noises you can hardly hear (no radio, fan on low, stopped, idling, no traffic passing by, and the mic still barely picks it up). This is basically "looking for a problem" and potentially not understanding how air conditioning works. Gurgling or sputtering can be a little different. This indicates that the high pressure side of the system is not full of liquid as it should be and there are pockets of gas in the liquid line. This can indicate a low refrigerant charge situation. F10 owners have also described a "water fall" trickling sound. This usually ends up being low coolant (i.e. antifreeze, not refrigerant) or air in the cooling system and hearing it does not require the air conditioning (snowflake) to be on, but is accentuated with coolant is flowing through the heater core. Losing refrigerant slowly (over the course of several years) is normal/allowable but needing a recharge annually is not. Chasing a leak you can't find must be very frustrating.
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