Struggling Aircon
Thread Starter
Junior Member
Joined: Jan 2021
Posts: 59
Likes: 10
From: Perth, Western Australia
B180 (W245), A-180 (W176) & GLC-250d (X253) <previously GL320CDI (X164)>
Struggling Aircon
Hi All
I am not sure if it is just the aircon system in the GLC which might be underpowered?
In the hot temperature in WA, up 40 degC on some days, I found that I need to run the aircon at fan speed 5 (out of 7) at least to cool the cabin. Even then, speed 5 can be quite a struggle.
I've changed the cabin air filters (internal and external), still not much difference. Running at speed 7 is like running a turbo prop engine from the sound.
My missus A-class cools the cabin quickly at speed 2 of 6.
Similarly, when I had the GL320CDI, fan speed 2 or 3 (our of 7) is sufficient on hot days
Anyone else has issue with their aircon on HOT days?
I am not sure if it is just the aircon system in the GLC which might be underpowered?
In the hot temperature in WA, up 40 degC on some days, I found that I need to run the aircon at fan speed 5 (out of 7) at least to cool the cabin. Even then, speed 5 can be quite a struggle.
I've changed the cabin air filters (internal and external), still not much difference. Running at speed 7 is like running a turbo prop engine from the sound.
My missus A-class cools the cabin quickly at speed 2 of 6.
Similarly, when I had the GL320CDI, fan speed 2 or 3 (our of 7) is sufficient on hot days
Anyone else has issue with their aircon on HOT days?
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
Likes: 5,322
From: San Francisco Bay Area
2019 C63CS
Well, a GLC has a larger cabin volume than an A class, so a) more hot air needs to be cooled, and b) more surface area for the sun to hit and heat up the cabin. But above all, why are you manually messing with the fan speed in the first place? The system is designed to automatically cool down the interior and then keep it at the desired temperature. Leave it on auto and let it do what it was designed for. It does a better job than you manually adjusting the fan speed. I can understand the fan noise concern, but you won't cool down the interior unless it pumps in enough cool air. It might run at a high fan speed initially, but it should quickly lower it. In my experience the MB AC is on the quieter side in the different models I've driven so far. It factors in many things, even the amount of sun that hits the car and optimizes the amount of cold air blowing in to keep you comfortable. It can only do all that if you let it, though.
Last edited by superswiss; Jan 26, 2022 at 06:25 PM.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,040
Likes: 161
From: Melbourne, Australia
2016 GLC 250d AMG pack, 2017 GLC Coupe 250d AMG pack , 2002 BMW 330Ci convertible, 2021 BMX X1 sD20i
Currently experiencing 37c for the past week. GLC has been excellent. Setting on Auto, set and forget.
Front side windows light tint and UV treatment. Sunroof panda blind closed. Always use front screen sunshade when parked, makes a huge difference and allows AC to run more effective. Sometimes run on recycle to allow car to chill inside air and not struggle to cool hot outside air - eventually switch back to fresh air intake, still set to auto.
I use AC all year around to keep compressor and fittings in use and not let seals dry out. Get system tested for leaks and have it re-gassed to factory settings.
close rear seat outlets on centre arm rest ?? Check settings for footwell, face and windscreen priority ??
Good luck.
Front side windows light tint and UV treatment. Sunroof panda blind closed. Always use front screen sunshade when parked, makes a huge difference and allows AC to run more effective. Sometimes run on recycle to allow car to chill inside air and not struggle to cool hot outside air - eventually switch back to fresh air intake, still set to auto.
I use AC all year around to keep compressor and fittings in use and not let seals dry out. Get system tested for leaks and have it re-gassed to factory settings.
close rear seat outlets on centre arm rest ?? Check settings for footwell, face and windscreen priority ??
Good luck.
MBWorld God!
Joined: Dec 2019
Posts: 32,217
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The colour of your vehicle also plays a role in how much heat your vehicle gets, if your vehicle's colour is on the darker side it may attract more heat from the sun while lighter colours usually reflects the sunlight more (Just my opinion though). Are both of your vehicles tinted?
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
Likes: 5,322
From: San Francisco Bay Area
2019 C63CS
The colour of your vehicle also plays a role in how much heat your vehicle gets, if your vehicle's colour is on the darker side it may attract more heat from the sun while lighter colours usually reflects the sunlight more (Just my opinion though). Are both of your vehicles tinted?
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Joined: Dec 2019
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That is indeed true. Auto Trader actually took two nearly identical vehicles, one white and one black and left them in the sun for a few hours and then measured the cabin temperature. The black car was at 130F, while the white car was only at 113F. They then tested how quickly each one cooled down once the AC was running and after 10 minutes the white car cooled down to 84F and the black car was still at 91F. Interior color also plays a role. A black interior will absorb and store more heat than a lighter colored interior.
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Joined: Nov 2021
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From: Hong Kong, China
2021 S450 4Matic
My bet is also on a malfunctioning compressor/thermostat or inadequate coolant, as fan speed 2 (out of 6) of an A-class and 2-3 (out of 7) of your old GL320CDI can cool in hot days in your region.
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Thread Starter
Junior Member
Joined: Jan 2021
Posts: 59
Likes: 10
From: Perth, Western Australia
B180 (W245), A-180 (W176) & GLC-250d (X253) <previously GL320CDI (X164)>
Hi All
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
Likes: 5,322
From: San Francisco Bay Area
2019 C63CS
Hi All
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
As I said before, I find the MB AC systems some of the quietest. It's one of the first things I noticed when driving my C63 in the summer. My previous Audi RS5 was super noisy in comparison on a hot summer day. Both black cars BTW with black interiors and panoramic sunroofs, and both with thin cloth shades. My RS5 even had a rear window shade that I kept closed during the day.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,040
Likes: 161
From: Melbourne, Australia
2016 GLC 250d AMG pack, 2017 GLC Coupe 250d AMG pack , 2002 BMW 330Ci convertible, 2021 BMX X1 sD20i
Hi All
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
Thanks for the many feedbacks.
Yup, I do admit my car is grey, so might absorb more heat. But my previous GL320CDI is grey too and has a bigger compartment.
Much cooler when I entered it during hot summer. The GL320CDI has a sun roof too and the under glass layer is made of a similar roof liner material while the GLC had a thin sun shade material. Could that be the reason?
I never had to put to AUTO in my previous rides (in the GL320CDI, XC90, Prado and even the MUX).
I did on the GLC but the sound of the fan is extremely loud (like turbo prop engine and/or motorboat).
Other than that, it is a great car
Never had issue with noise or radiant heat from roof with blind closed.
Yes open all front vents, check under both front seats that nothing is blocking the floor vents under your seats.
Check your default air settings re where air is being directed, screen, front, footwell ?
Also make sure you have not set your cabin temp to 16C or max cooling, it will never go quiet.
Set your cabin temp and 22c or 23c and see how that goes. On days here at 37-40c a cabin setting on auto at 23c is perfect, also sync your driver side and passenger side temp settings to be the same.
Auto works perfectly.
Good luck
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
Likes: 5,322
From: San Francisco Bay Area
2019 C63CS
+1...yes I forgot to ask what you had the temperature set to. The temperature setting is sometimes misunderstood. It's not the temperature of the air that's coming out of the vents. It's the desired cabin temperature. Works just like the thermostat in your house. You set the temperature and the thermostat does the rest. Sometimes people think setting a lower temperature will cool the cabin faster, but that's not how it works.
Last edited by superswiss; Jan 27, 2022 at 02:38 AM.
Thread Starter
Junior Member
Joined: Jan 2021
Posts: 59
Likes: 10
From: Perth, Western Australia
B180 (W245), A-180 (W176) & GLC-250d (X253) <previously GL320CDI (X164)>
Thanks for the tips.
Will give a go on the setting on my way home this afternoon.
Not that hot though at 32degC (predicted).
But will be this weekend when temperature goes to the higher 30's and maybe peak at 40 degC
Will give a go on the setting on my way home this afternoon.
Not that hot though at 32degC (predicted).
But will be this weekend when temperature goes to the higher 30's and maybe peak at 40 degC
