High Fan Speed/Noisy ATC
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
Posts: 5,113
Likes: 57
From: Southwest USA
Another round of ICE
High Fan Speed/Noisy ATC
I usually hang out on the W204, as that's mine, but my wife's ATC performs so differently than the system in the C Class, I was looking for opinions/experience. In the C, when set on AUTO, the system will find the proper temperature and the fan will settle down while it very nicely holds the ambient temp in the cabin. In the W211, it sounds like we're on the edge of a hurricane, and even after the temp is comfortable, the fan is always running higher than expected, generating more noise than desired. We frequently have to simply take the fan down manually. I know this is all governed by software...any ideas if this is abnormal? Thanks!
P.S. Yes, I did search first!
P.S. Yes, I did search first!
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
Posts: 5,113
Likes: 57
From: Southwest USA
Another round of ICE
This sure is a quiet forum...I guess that goes with being an E Class? 100 people have read this post and no one has any experience or comments to share? 
Senior Member
Joined: Apr 2005
Posts: 293
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From: Austin, TX
'13 E550 W4
My AC is very loud from the outside, sounds like a turbo train is coming. No problems with noise inside, although I wish the blower would produe more thrust for front and back passengers.
Member
Joined: Jul 2004
Posts: 174
Likes: 1
From: San Antonio, Tx
2008 S550 designo
My 08 E350 was doing the same. I checked all the vents and found the passenger side and the rears closed. Opening those helped somewhat, but it still seems to run faster/louder than it should. Next time I'm in for service, I'm going to ask if there is a software update available.
Senior Member
Joined: Jul 2007
Posts: 421
Likes: 14
From: Bay Area
2004 E500 CLK320
On my 2004 E500, when set the temp to auto mode, the fan runs at full blast for a long time even after the temperature reaches a "comfortable" level, as you've described. And yes, I usually manually lower the fan speed after reaching a comfortable temperature. I think the fan motor is much powerful than the C class partly due to more space volume to cool. I had a 1988 C280 previously, and the fan was no where as powerful & loud as this E500. The noise generated from the engine is more like a hurricane -- it's definitely a force to be reckoned with.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2009
Posts: 5,113
Likes: 57
From: Southwest USA
Another round of ICE
Thanks everyone! 
Based on your comments, it certainly seems that this is at least not an individual defect with my car. I will also ask if there is a software update which calms the fan down once the target interior temp is achieved. I understand the issue of relative interior volume requiring greater output, but this does seem quite disproportionate and certainly much louder and higher fan speeds than ATC systems in comparably or larger sized competitive makes.
Based on your comments, it certainly seems that this is at least not an individual defect with my car. I will also ask if there is a software update which calms the fan down once the target interior temp is achieved. I understand the issue of relative interior volume requiring greater output, but this does seem quite disproportionate and certainly much louder and higher fan speeds than ATC systems in comparably or larger sized competitive makes.
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MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
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From: Ft. Lauderdale Area, USA
2015 ML 350
On my 2004 E500, when set the temp to auto mode, the fan runs at full blast for a long time even after the temperature reaches a "comfortable" level, as you've described. And yes, I usually manually lower the fan speed after reaching a comfortable temperature. I think the fan motor is much powerful than the C class partly due to more space volume to cool. I had a 1988 C280 previously, and the fan was no where as powerful & loud as this E500. The noise generated from the engine is more like a hurricane -- it's definitely a force to be reckoned with.
The number on the display when you are comfortable will surprise you... its NOT the same number you have your House thermostat set to.
Thats why you feel as if the blower stays on high longer than necessary. ...remember, whenever your dash control unit is in MAX mode, (Manual MAX or regular DEF modes) the radiator fan goes into that screaming loud mode under the hood to dissipate heat.
Last edited by Barry45RPM; Jul 3, 2010 at 10:09 PM.
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Junior Member
Joined: Aug 2009
Posts: 39
Likes: 0
05 e500 & 11 sti
Well said barry. OP, your "comfortable" temperature is subjective. So even if you feel "comfortable" most likely youre not at the set temperature yet. Honestly I doubt theirs a software upgrade for something that is working the way it should. Merc obviously knew that most of their owners are impatient and want instant gratification, and the only way to achieve that in the shortest amount of time, is to use a higher fan speed. The downside is increased noise. Seriously i think youre just being overly sensitive about something that is totally in your control. As with all things in life, you cant have it all, compromises will have to be made.
I agree my e500 makes a lot of fan noise on auto, but like what was already suggested, turn the temp up or manually control the fan.
Happy 4th all!!
I agree my e500 makes a lot of fan noise on auto, but like what was already suggested, turn the temp up or manually control the fan.
Happy 4th all!!
MBWorld Fanatic!
Joined: Mar 2004
Posts: 5,017
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From: Ft. Lauderdale Area, USA
2015 ML 350
That's probably why on the 07s > the second you press Auto, the fan speed indicator dissapears from the display. (on th 06s < the fan speed indicator was always on display). They probably wanted to get peoples mind off fan speed.
On a really hot day, the A/C can't pull the cabin speed down to a real 69 anyway, so if you raise the temp to a setting the unit can satisfy, your interior fan will come off HI, and your underhood fan will drop in speed too, not making that Everglades Boat type of racket.
On a really hot day, the A/C can't pull the cabin speed down to a real 69 anyway, so if you raise the temp to a setting the unit can satisfy, your interior fan will come off HI, and your underhood fan will drop in speed too, not making that Everglades Boat type of racket.
Member
Joined: Jul 2004
Posts: 174
Likes: 1
From: San Antonio, Tx
2008 S550 designo
Well said barry. OP, your "comfortable" temperature is subjective. So even if you feel "comfortable" most likely youre not at the set temperature yet. Honestly I doubt theirs a software upgrade for something that is working the way it should. Merc obviously knew that most of their owners are impatient and want instant gratification, and the only way to achieve that in the shortest amount of time, is to use a higher fan speed. The downside is increased noise. Seriously i think youre just being overly sensitive about something that is totally in your control. As with all things in life, you cant have it all, compromises will have to be made.
I agree my e500 makes a lot of fan noise on auto, but like what was already suggested, turn the temp up or manually control the fan.
Happy 4th all!!
I agree my e500 makes a lot of fan noise on auto, but like what was already suggested, turn the temp up or manually control the fan.
Happy 4th all!!
The reason I don't believe we are being "overly sensitive" is this is my 8th Mercedes and the only one that has done this. Yes, comfort is subjective and yes, each car has had it's own temperature setting to make me comfortable. But this is the only one that has run at noisy fan speeds continuously. No matter the temperature setting, the fan seems to run too fast even after cooling the car down. Raising the temperature does not seem to make that much difference - it still runs too high. My other cars will lower the fan to imperceptable levels at times, but not this one.
Super Member
Joined: Aug 2009
Posts: 600
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From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
When the fan is on full blast, it really does sound like a crazy hurrican with a really faint wine to it. Though it was something but I guess it just normal. As long as it keep me cool with cold air, I am good. How often do people drive with the fan at full blast for a longer period of time anyways???? Not very long.
Senior Member
Joined: Sep 2006
Posts: 413
Likes: 3
2003 E320
It appears to me that the engine bay fans are stuck in the maximum mode. I have an older 211 but it does calm down once the user dials up the T/Stat.
Personally, I applaud the way it works. A black car in the south can get pretty hot when parked. The blower and cooling fans come to life at full bore instantly when "auto" is pushed and 70 degrees on the stat. Yeah, the noise is pretty bad but mostly outside of the car.
Others may be annoyed but I enjoy the delivery of icy air and plenty of it. Intuitively, I would say that it reaches a comfortable level in the cabin in about 2 minutes while our silver Maxima takes about 4-5. Those engine bay fans draw plenty of electrical power. Continuous high speed running at idle will put a serious current draw on the battery. I have no idea what is causing yours to stay at max but it is not what I know as normal.
Personally, I applaud the way it works. A black car in the south can get pretty hot when parked. The blower and cooling fans come to life at full bore instantly when "auto" is pushed and 70 degrees on the stat. Yeah, the noise is pretty bad but mostly outside of the car.
Others may be annoyed but I enjoy the delivery of icy air and plenty of it. Intuitively, I would say that it reaches a comfortable level in the cabin in about 2 minutes while our silver Maxima takes about 4-5. Those engine bay fans draw plenty of electrical power. Continuous high speed running at idle will put a serious current draw on the battery. I have no idea what is causing yours to stay at max but it is not what I know as normal.
Super Member
Joined: Aug 2009
Posts: 600
Likes: 2
From: Northern California
09' E350 AMG Sport, 09' C300, 03' Honda S2K
Maybe this is one reason why our battery are so large comparing with other cars. I took a look at our battery in the truck and have to say that it is by far not a normal size that I see in most sedan cars.
Member
Joined: Jul 2004
Posts: 174
Likes: 1
From: San Antonio, Tx
2008 S550 designo
The thread has moved off subject. The original poster and I are talking about the blower motor running fast, not the radiator fan.
Yes, the radiator fan sounds like a hurricane, but that is normal for these, and a lot of other cars nowadays. The blower fan on our cars also runs high (in our opinion anyway,) causing the interior of the car to be noisy and cold. It does not seem to slow enough once the interior of the car cools down. Raising the temperature helps somewhat, but the fan seems to still run faster than any other car I've owned maintaining temperature.
Anyway, just thought I'd try to clear up what we are experiencing.
Yes, the radiator fan sounds like a hurricane, but that is normal for these, and a lot of other cars nowadays. The blower fan on our cars also runs high (in our opinion anyway,) causing the interior of the car to be noisy and cold. It does not seem to slow enough once the interior of the car cools down. Raising the temperature helps somewhat, but the fan seems to still run faster than any other car I've owned maintaining temperature.
Anyway, just thought I'd try to clear up what we are experiencing.
Junior Member
Joined: Apr 2014
Posts: 23
Likes: 3
W211 E500 2003
Hi, I bought my first MB about two months ago, and since then it has been a problem after another. after changing all the front suspension and mounts, I turned the car on and the radiator fan kicked about 10-15 sec, I think it has nothing to do with me replacing mounts since I did not disconnect any wires while working on the suspension and mounts, but I unplugged the fan's connection (the one on the fan closer to the passenger side head light) and I saw some kind of green corrosion on one of the pins the smaller pin hole on the left side of the plug.
I just want to add that my AC have been out since i bought the car, could that be a related matter?
Please help!!!!
I just want to add that my AC have been out since i bought the car, could that be a related matter?
Please help!!!!
Senior Member
Joined: Aug 2014
Posts: 337
Likes: 20
From: Charlotte, NC
2005 E320 CDI, 2015 GLA 250
My fan was making squeaking noises about four years ago and I replaced the blower. However, it is now making the same howling noise others have commented on. My wife complains about it so it isn't just in my head.
Will a new blower quiet it down or is there no fix but to manually turn it down?
Thanks,
Peter
Will a new blower quiet it down or is there no fix but to manually turn it down?
Thanks,
Peter
