When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
it may be a problem but the GLB has a lot of glass and if you have the full glass sunroof, these all add to the heat, not to mention the color of the car. There is a maximum number of degrees any A/C can drop the temperature. I think its about 20 degrees. If you use the recycle it will be cooling the inside air which will eventually be cooler than the outside air.
Also, not sure of the controls on your car but if it has a max button I would use this. This puts the AC in the recycle mode. This should eventually get the inside temp down quicker.
We have 3M Crystalline tints all around , including WINDSHIELD and the pano sunroof.
Recirculation and set the AC temperature to lowest temperature MAX, and etc. A couple of weeks ago it was 105+ F and the AC was just blowing hot air from the get go. Then we were on the freeway going 70 mph for a good 45 minutes and the AC was just blowing HOT AIR. I MEAN IT WAS HOT IN THE CAR!! Went on for another half an hour..... Highway cruising....same HOT AIR THE ENTIRE JOURNEY. Gave up and arrived at destination where we had our other vehicles...... Lexus RX450h or LX570. OUT of curiosity we drove both in the hot weather.....both the RX450h and the LX570 both cooled down the interior in a jiffy.....less than 10 minutes I had to adjust the temperature from lowest/MAX to 70 F bc it was already getting TOO COLD!!! WE HAD NEVER EVER HAD ANY AC problems with ANY OF THE LEXUS WE HAD. One we had several years ago was a prior gen LX470 since new and sold it with 280K+ miles on the ODO WITHOUT ANY ISSUES, NONE WHATSOEVER. Not too sure about this GLB250????
The entire trip my wife kept saying, SEE, I TOLD YOU SHOULD HAVE GOTTEN ANOTHER LEXUS AND NOT THIS POS!!! Oh well, too late now. LOL
The LX got lots more interior volume to cool down PLUS a lot more GLASS areas VS the MB GLB250.
IDK, maybe there is a design flaw with the GLB250?
SO after getting back from the MB DEALER and was told all was normal...... We had not had any more issues with the AC, but it has not been that hot since.... We will keep an eye out for the AC and report back.....
Originally Posted by Isawelvis
it may be a problem but the GLB has a lot of glass and if you have the full glass sunroof, these all add to the heat, not to mention the color of the car. There is a maximum number of degrees any A/C can drop the temperature. I think its about 20 degrees. If you use the recycle it will be cooling the inside air which will eventually be cooler than the outside air.
Also, not sure of the controls on your car but if it has a max button I would use this. This puts the AC in the recycle mode. This should eventually get the inside temp down quicker.
I'm only responding to try to help. I had a 2000 Dodge Durango. Great car. But the a/c seemed weak. I live in Houston where the summers are hot. But I happened to read somewhere that you can do some maneuvers to make things better. The Durango sat outside in the work parking lot all day, on asphalt pavement. The car was baking from the top and the bottom.
So, the procedure was to set the a/c on the outside air setting, not recirculate. All the interior surfaces and the air inside are 130 deg plus. Open all the windows and drive for a few minutes. That replaces the 130 air with 95 air and helps cool down the dashboard through which all the air is coming. Then roll up the windows but don't use recirculate. The a/c would catch up and all would be ok. Recirculate at the beginning just keeps 130 deg air going around in circles. In fact after that I hardly ever used recirculate. That had an added benefit of preventing mold build up in the system. We're still in Hou and own a '14 ML350 and a '14 GL450. I still do the window opening routine if the car has been sitting out.
You don't say if you still have the problem coming out of the garage or when the car is cool to begin with. Go to an auto parts store and get an a/c vent thermometer (pictures). Put it in one of the center vents. Don't try the above until you get readings when the circumstances are as you first described. Then park the car in the sun for awhile and let the interior heat up. Try the above and see what readings you now get. I got 41 deg at the center vent once I started doing the above. BTW the temp in my garage was 82 according to the vent thermometer. Good luck,
This is the fourth MB we've had. We still got the GLA which the AC works fine.
I still think that the AC unit in the GLB is not up to snuff bc they used a smaller capacity AC unit to cut costs. Therefore the AC can not keep up when it's EXTREMELY HOT OUTSIDE.
We had been driving for a little over an hour and the AC in the GLB was still blowing HOT air? We tried rolling all windows down and switch the vent to outside then recirculating air. NOTHING but hot air. We even switched to SPORT mode to COMFORT mode...... Still HOT AIR.
Maybe the MB DEALER made some adjustments to the AC but still told us all normal to "preserve" the GLB reputation? IDK. But now the AC seems fine. But it had not gotten that hot again yet. My wife and kids now INSISTS on taking the Lexus LX570 or the RX450h for any trip over 15 minutes bc she does not want to be riding in a HOT car again. I don't blame them.
Will keep you all posted on the AC on the GLB.
Originally Posted by pjw1967
I'm only responding to try to help. I had a 2000 Dodge Durango. Great car. But the a/c seemed weak. I live in Houston where the summers are hot. But I happened to read somewhere that you can do some maneuvers to make things better. The Durango sat outside in the work parking lot all day, on asphalt pavement. The car was baking from the top and the bottom.
So, the procedure was to set the a/c on the outside air setting, not recirculate. All the interior surfaces and the air inside are 130 deg plus. Open all the windows and drive for a few minutes. That replaces the 130 air with 95 air and helps cool down the dashboard through which all the air is coming. Then roll up the windows but don't use recirculate. The a/c would catch up and all would be ok. Recirculate at the beginning just keeps 130 deg air going around in circles. In fact after that I hardly ever used recirculate. That had an added benefit of preventing mold build up in the system. We're still in Hou and own a '14 ML350 and a '14 GL450. I still do the window opening routine if the car has been sitting out.
You don't say if you still have the problem coming out of the garage or when the car is cool to begin with. Go to an auto parts store and get an a/c vent thermometer (pictures). Put it in one of the center vents. Don't try the above until you get readings when the circumstances are as you first described. Then park the car in the sun for awhile and let the interior heat up. Try the above and see what readings you now get. I got 41 deg at the center vent once I started doing the above. BTW the temp in my garage was 82 according to the vent thermometer. Good luck,
Thanks for letting me know. BTW I was planning on getting a GLB CPO in a year or two. If I do, I guess I'll buy in the summer to see how the a/c does. In the meantime, suggest you get the vent thermometer to start documenting the problem. First go out in the Lexus when it's really hot and check the vent temp. Take a photo of it and the outside air temp and the time of day. Then do the same with the GLB. If you're gonna get anywhere with the dealer you have to document. Do it for a few days with the GLB. When you go back to the dealer, ask him if they can take you for a short ride in a GLB that's been sitting in the sun. Bring the vent thermometer but don't tell them you're going to test that car. See what happens. It may just temporarily get rid of that helpless feeling, or goose the dealer into looking harder at your car.
Thanks for letting me know. BTW I was planning on getting a GLB CPO in a year or two. If I do, I guess I'll buy in the summer to see how the a/c does. In the meantime, suggest you get the vent thermometer to start documenting the problem. First go out in the Lexus when it's really hot and check the vent temp. Take a photo of it and the outside air temp and the time of day. Then do the same with the GLB. If you're gonna get anywhere with the dealer you have to document. Do it for a few days with the GLB. When you go back to the dealer, ask him if they can take you for a short ride in a GLB that's been sitting in the sun. Bring the vent thermometer but don't tell them you're going to test that car. See what happens. It may just temporarily get rid of that helpless feeling, or goose the dealer into looking harder at your car.
I have the same issue! These days here in central California the temperature has been over 100 degrees. Where I work there is barely any shade available. When the temperature is over 108 degreed the ac takes approx. 20 to 30 mins to get cold. This is becoming an issue because my previous CLA 250 works fine during the heat. Like you, I spent close to $1000 on ceramic tint job that supposes to reduce the heat but it doesn't feel like that. I have to schedule an appt. to get Mercedes to take a look at it. Let me know if you got your issue fixed.
Update after three days of temperatures displayed over 115 degrees on dash. All three days I used my sun visor from Mercedes and the ac worked fine. So my theory is that some type of electronic in the dashboard is affected by the heat from windshield even though I have ceramic tint installed. I see other post about adding Freon would not recommended the system could lose pressure or become overcharged. Take you car to get professional inspected and repaired. Hope this helps.
Last edited by Smoothbruda35; Aug 18, 2020 at 04:09 PM.
My wife didn't have time to get to the MB dealership in time before they closed. Of course after she got home the AC is working again.
Both times when the AC failed the ambient temperature is over 105 F. AND while the GLB is moving at highway speeds the AC was just blowing HOT AIR. After the Highway driving arriving at the house while idling, the AC decided to work!!!
I ordered the AC thermometer on AMAZON and will videotape the next time the AC fails again to show the MB Dealership if they tell me again "All normal"!!!
Originally Posted by Smoothbruda35
I have the same issue! These days here in central California the temperature has been over 100 degrees. Where I work there is barely any shade available. When the temperature is over 108 degreed the ac takes approx. 20 to 30 mins to get cold. This is becoming an issue because my previous CLA 250 works fine during the heat. Like you, I spent close to $1000 on ceramic tint job that supposes to reduce the heat but it doesn't feel like that. I have to schedule an appt. to get Mercedes to take a look at it. Let me know if you got your issue fixed.
When you turn on the AC, do you feel or hear a little drag on the engine (when it works and doesn't work)? I'm guessing here, but I wonder if your compressor is not engaging. When you turn on the AC, it energizes the compressor pulley which connects the compressor to the drive belt. If for some reason the pulley doesn't get energized the compressor never comes on to make cool air.
When you turn on the AC, do you feel or hear a little drag on the engine (when it works and doesn't work)? I'm guessing here, but I wonder if your compressor is not engaging. When you turn on the AC, it energizes the compressor pulley which connects the compressor to the drive belt. If for some reason the pulley doesn't get energized the compressor never comes on to make cool air.
In another group elsewhere on the internet someone said that they were experiencing the same problem and it was determined that the AC system was overfilled. Once they had service department relieve some of the pressure their problems regarding AC blowing hot stopped completely.
It does sound more to me like the compressor isn't engaging though. Wondering if you cycle on and off many times it eventually comes on.
I would suggest taking it to the MB dealer while it's actually blowing hot air so they can observe the problem while it's actually happening. That'll probably be a pain to do but it might be the only way to prove to the MB dealer there's a problem. I agree that this isn't normal.
So far each and every time this had happened the GLB manages to COOL down after about 45 minutes to an hour by the time we make it to the selling MB dealer (local at home).
A couple of times when we FIRST started the GLB and heading out from home the AC is not working and blowing HOT air.... We usually have time restraints to get to where we are going and NOT have the LUXURY of just going to our local (selling) MB dealer and hang around for half an hour to an hour ...... We were just too spoiled by our many Lexi vehicles where all were trouble free 😂
We will have to video record with an AC thermometer to document that the AC is not working as per another member's suggestion.
Will keep you all posted.
Originally Posted by 190Efan
I would suggest taking it to the MB dealer while it's actually blowing hot air so they can observe the problem while it's actually happening. That'll probably be a pain to do but it might be the only way to prove to the MB dealer there's a problem. I agree that this isn't normal.
We had the same problem on our A220, The dealer was able to replicate the problem and fixed it. Florida actual temps are not as hot, but in the sun ...
We had the same problem on our A220, The dealer was able to replicate the problem and fixed it. Florida actual temps are not as hot, but in the sun ...
Had something similar on my wife's past c300, on hwy when hot the cool air started getting warm then hit, fan worked fine, just no cooling. Many trip to dealer and if course they could not duplicate a hwy trip. I self diagnosed and it was the evaperator freezing up, the compressor worked so good and there was not enough air across it and the water from the air just froze. Let the car sit a little and the ice melted and back to normal. The air coming out of the vents should be in the 50s if the system is working properly. The car is new but on older cars it could be the cabin filter, gligged and not enough air getting through. I don't remember what the dealer did but I think some sensor, it was a few MBs ago. Video with your phone when it happens and show your little thermometer. Home AC will only drop temp from inlet air to outlet about 20 degrees but auto air should out out 50-60 degree air no matter what, especially at hwy speeds. I'm in Texas, 104 a few days ago and freezing air from my C43.
Had something similar on my wife's past c300, on hwy when hot the cool air started getting warm then hit, fan worked fine, just no cooling. Many trip to dealer and if course they could not duplicate a hwy trip. I self diagnosed and it was the evaperator freezing up, the compressor worked so good and there was not enough air across it and the water from the air just froze. Let the car sit a little and the ice melted and back to normal. The air coming out of the vents should be in the 50s if the system is working properly. The car is new but on older cars it could be the cabin filter, gligged and not enough air getting through. I don't remember what the dealer did but I think some sensor, it was a few MBs ago. Video with your phone when it happens and show your little thermometer. Home AC will only drop temp from inlet air to outlet about 20 degrees but auto air should out out 50-60 degree air no matter what, especially at hwy speeds. I'm in Texas, 104 a few days ago and freezing air from my C43.
The June 16th entry is for the A/C and has a document the dealer can use to fix it.
This vehicle is brand new and already there are 4 pages of communications filed with NHTSA concerning various issues with this vehicle. If I was you, I would print the entire 4 pages and have your vehicle inspected for all of the issues noted in these NHTSA communications when you next take it in for the A/C issue. Just my 2 cents of advise.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
