Poor AC performance
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 26
Likes: 6
GLE450
Poor AC performance
Driving my 450 through the heat waves I find the AC performance pretty marginal. I have to keep the set temp at about 16'C to get much cool air, and the fan is really loud at that setting. I remember in the winter, the fan was also loud when heat was called for so I suppose these cars just have loud fans. However, I don't remember a problem getting enough heat. None of our other cars have such poor AC performance and that sample includes a BMW that is 13 years old and a 10 year old Audi.
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
Member
Joined: Jan 2020
Posts: 203
Likes: 103
From: Tucson, Arizona
2004 CLK320 Cab, 2020 GLE350
Driving my 450 through the heat waves I find the AC performance pretty marginal. I have to keep the set temp at about 16'C to get much cool air, and the fan is really loud at that setting. I remember in the winter, the fan was also loud when heat was called for so I suppose these cars just have loud fans. However, I don't remember a problem getting enough heat. None of our other cars have such poor AC performance and that sample includes a BMW that is 13 years old and a 10 year old Audi.
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
MBWorld Fanatic!
Joined: Sep 2018
Posts: 3,254
Likes: 936
From: New Orleans Area
2015 E400 Sedan
What was engine RPMS?
Speed?
AMbient temp?
Sun shine?
Humidty?
All these things affect AC performance.
If on interstate for 10-15 mins and you are not cool... then I would have it checked...
Speed?
AMbient temp?
Sun shine?
Humidty?
All these things affect AC performance.
If on interstate for 10-15 mins and you are not cool... then I would have it checked...
Member
Joined: May 2020
Posts: 180
Likes: 17
From: New York
2025 e450
I just posted this exact question on FB. I have a 2020 350 not even 2 months old. There has got to be something wrong with the system. It cools
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
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From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
I just posted this exact question on FB. I have a 2020 350 not even 2 months old. There has got to be something wrong with the system. It cools
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
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From: New York
2025 e450
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From: Boise
2024 GMC Canyon Denali..... 2018 Audi SQ5
When my MBUX Control module started going bad I had some different but unusual issues that might repeat or might not repeat. I made some recordings and between my Dealer and Tech support they figured it out. I was convinced that it was software code conflicts and insisted that’s what it almost had to be. A year later and everything is still working.
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Super Member
Joined: Jan 2020
Posts: 791
Likes: 412
From: Fredericksburg, VA
2020 Mercedes GLE350 4Matic; 2023 Tesla Model Y
Driving my 450 through the heat waves I find the AC performance pretty marginal. I have to keep the set temp at about 16'C to get much cool air, and the fan is really loud at that setting. I remember in the winter, the fan was also loud when heat was called for so I suppose these cars just have loud fans. However, I don't remember a problem getting enough heat. None of our other cars have such poor AC performance and that sample includes a BMW that is 13 years old and a 10 year old Audi.
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
I have seen the thread about the AC failing and blowing hot air, but my own issue is not a failure. Cooling still functions. It is just that the system is barely able to cope. Is this the way the all are or is my car in the process of failing?
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 26
Likes: 6
GLE450
Thanks for the replies. Some of you have no problem so a well adjusted GLE can manage a moderately hot and humid day. In contrast, mine can only keep the interior on the warm side of comfortable, even though the heat and humidity here is not that bad (Canada). I think because the air isn't very cold, the system tries to move a lot of it - causing the loud fan. If I turn down the fan, the car gets too warm.
It does work, but something is failing. I will take it in when I can get an appointment scheduled.
It does work, but something is failing. I will take it in when I can get an appointment scheduled.
Senior Member
Joined: Mar 2016
Posts: 446
Likes: 134
From: Montreal, QC
2020 GLE450 4Matic AMG-Line
I too have issues with my Thermotronic HVAC.
There is no air at all coming out of the vent to the left of the steering wheel regardless of fan speed.
When temps and fan speed are synced with the driver's position, all four zones work, but as soon as I change any setting for either of the two zones in the rear, the fan speed drops to the lowest setting from the rear center console, regardless of what fan speed intensity is displayed.
At least the B-Pillar vents continue to blast air.
There is no air at all coming out of the vent to the left of the steering wheel regardless of fan speed.
When temps and fan speed are synced with the driver's position, all four zones work, but as soon as I change any setting for either of the two zones in the rear, the fan speed drops to the lowest setting from the rear center console, regardless of what fan speed intensity is displayed.
At least the B-Pillar vents continue to blast air.
Super Member
Joined: Apr 2020
Posts: 778
Likes: 420
From: Pennsylvania
2024 GLE 450 4matic
Make sure your left and right zones are sync'd as I've seen a large difference between the two cause erratic operation. They do operate independently but always felt it was more of a placebo effect for the co pilot.
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Joined: Apr 2019
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A
What I realized recently is that is doesn't cool super efficiently, if have enabled for it to blow on feet, center, and windshield at the same time. Seems best setup is center and feet.
Also, synced, as Lucky mentioned. What I really find annoying as that the windshield has no solar insulation at all, I am looking at some ceramic window films and might do that.
P.S. paging @places so he can say that the GLE is "full of problems"
Also, synced, as Lucky mentioned. What I really find annoying as that the windshield has no solar insulation at all, I am looking at some ceramic window films and might do that.
P.S. paging @places so he can say that the GLE is "full of problems"
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From: Florida
2025 Porsche Cayenne S Hybrid + 2023 EQS 580 SUV
Junior Member
Joined: Jun 2020
Posts: 32
Likes: 14
From: Frisco, TX
2013 BMW 5 Series, 2020 GLE 350
I too was originally thinking that my AC was not as efficient as it should be, so i did an experiment.
Set the ac to the lowest temp (60F)
Outside temp was 98F
Set it to air circulate mode.
Fan speed at 3
Drove for 15 minutes so that the system had enough time to power up
and then parked the car and did a thermogun reading at the front vents. The readings were all over the place depending on where in the vent was i pointing the laser beam. ( Empty spaces vs horizontal slats vs chrome tip etc.)
But all 6 vents in the front showed a consistent ~35F as the MIN temparature. Hope this helps.
Set the ac to the lowest temp (60F)
Outside temp was 98F
Set it to air circulate mode.
Fan speed at 3
Drove for 15 minutes so that the system had enough time to power up
and then parked the car and did a thermogun reading at the front vents. The readings were all over the place depending on where in the vent was i pointing the laser beam. ( Empty spaces vs horizontal slats vs chrome tip etc.)
But all 6 vents in the front showed a consistent ~35F as the MIN temparature. Hope this helps.
Super Member
Joined: Jan 2020
Posts: 791
Likes: 412
From: Fredericksburg, VA
2020 Mercedes GLE350 4Matic; 2023 Tesla Model Y
I just posted this exact question on FB. I have a 2020 350 not even 2 months old. There has got to be something wrong with the system. It cools
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
fine but it blows louder than a loud radio. I’ve asked about the ‘Auto and ‘Blower speed but got different responses. I always keep in Auto but sometimes I could change the blower speed and sometimes I can’t. I know for sure that when the temp is set to LOW even putting the blower speed all the way down it’s Still blowing at full force and just as loud.
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A gaggle of MB's
Yes - highest fan levels are "loud" - the system however is quite efficient - and frankly I don't recommend "Low" temp setting - as running at Low for any period of time tends to "frost up" the evaporator which leads to a self-fulfilling expectation of decreased system efficiency.... I usually keep mine at 72 .. the system on hot days will take the fans to max - which I tolerate a min or two then manually set the fan down two levels - and return to Auto when I feel cool enough.
Yes - Crystalline DuPont film can be used to add UV/IR reduction to the front windshield - some swear by it - others use a fold-out on the windshield when parked in the sun.
Yes - Crystalline DuPont film can be used to add UV/IR reduction to the front windshield - some swear by it - others use a fold-out on the windshield when parked in the sun.
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Joined: Jul 2020
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From: Southeast US
2025 CLE AMG 53
MBWorld Fanatic!
Joined: Sep 2018
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From: New Orleans Area
2015 E400 Sedan
They are designed not to freeze over that only happens when low on refridgerant like a home system..
OR can happen when air flow is not enough...
but if it happens you have a problem. it is not normal
SO crank it low if hot.
But per manual one should set temp to what you want the inside temp to be, like your HOUSE...
The computers and stuff in the car will controll the compressor run time, air speed and blend doors to get cabin to that temp and hold it.
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Senior Member
Joined: May 2019
Posts: 444
Likes: 125
From: New England
2020 GLE 450 AMG exterior
Got mine in December, so there wasn't any need for A/C during the first six months I had it. First time I used the A/C, I set the temp to 65 and couldn't understand why it wasn't cooling me off. Finally, 15 minutes later at a stop light, I realized I hadn't actually pressed the A/C toggle switch on the dash. I had just assumed that setting the temperature would get me to the desired comfort level. Pretty dumb, but I doubt I'm the first or last person to do so.
Newbie
Joined: Jul 2020
Posts: 3
Likes: 1
2020 GLE350 4MATIC
I too was having problems with vehicle cooling and then discovered the Auto Fan was set to a minimum level and wasn't going to MAX.
Once I reset the Auto Fan speed to go to MAX, system worked fine.
It now goes to max fan and then slows down as temperature declines.
Once I reset the Auto Fan speed to go to MAX, system worked fine.
It now goes to max fan and then slows down as temperature declines.
