S-Class (W220) 1999-2006: S 320 CDI, S 320, S430, S 500, S 600

Cooling Fan noise

Old Jun 27, 2007 | 03:57 PM
  #1  
NazarKmet's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2007
Posts: 22
Likes: 0
2010 Mercedes S400
Exclamation Cooling Fan noise

Hi. how are you. When I turn on the AC my fan making a noise is it time to replace or any thing i can do with it. With out AC its work good. Thank you.
Reply
Old Jun 27, 2007 | 05:02 PM
  #2  
newton22's Avatar
MBWorld Fanatic!
 
Joined: Aug 2005
Posts: 4,574
Likes: 3
From: Sugar Land, TX
BMW E39
While idling, your fan usually doesn't spin (unless it's been sitting for a little while or it's hot out) until you start up the A/C.

Is your fan making an unusual noise?
Reply
Old Jun 27, 2007 | 05:12 PM
  #3  
fkong777's Avatar
Super Member
20 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Nov 2004
Posts: 687
Likes: 26
From: So Cal
07 GL450, 91 NSX, 12 Prius
when the AC goes to MAX the fan will spin at higher speed so it will have louder fan noise. if you turn down the AC to a lower level the fan will slow down.
Reply
Old Jun 28, 2007 | 10:34 AM
  #4  
NazarKmet's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2007
Posts: 22
Likes: 0
2010 Mercedes S400
Thank you.

I will test it.
Reply
Old Jul 2, 2007 | 10:30 PM
  #5  
T_Herbst's Avatar
Newbie
 
Joined: Mar 2007
Posts: 13
Likes: 0
From: Indiana
S500 W220
Aux Fan

Here is info from my post on this issue.
Auxiliary Fan, Control Unit – A few months ago the Radiator Fan was make some noise. While in the shop for oil change, they said the Auxiliary Fan Assembly need replaced for $1200. I checked it out myself and found that it was only the electric motor going. It appears that you can only purchase the complete assembly. I took the motor apart, and could only replace one bearing. The other bearing is on the end with the pulley, and it looks like its molded together and I can’t get it apart. So, I searched the Internet, and found an aftermarket AFA for $350. Took that motor off and used it. This works fine. It appears that the Auxiliary Fan Control Unit stopped working. also Why? I tested the AFCU with my voltmeter and it had 12v in, variable control voltage in, but 0v out. It appears this shorted out (stuck open). I beat it with my hammer, but no help. I have not opened it up yet. Has anybody done this? I currently have the motor connected to a relay. Now the fan runs all the time, at 100% and it’s loud, as in airflow loud. This really moves the air. I located a new AFCU, but $170, ouch again. Is it common for the AFCU to go out also?
Danger note: I connected the relay to a fuse that was 12v only when on. Mistake was not knowing what the fuse did. While I was driving 65mph the car shut off. I safely pulled off the road and seen the fuse that I tapped into was blown. Replaced the fuse, move the relay 12v to a different fuse, this one is working fine. On the relay I do have the 12v for the fan connected to the fans 60amp fuse. This is just the 12v control voltage.

To test further, (with car off and cool, you can also pull the 60a fuse if you want) pull the AFA away from the radiator and take the belt off. Spin the fan with your hand. Noise? Mine did not make any noise, so the fan was good. Start the car, run the AC, AFA motor ran and it was noisy. Motor bearing going out, so I did the above task.
Reply
Old Jul 3, 2007 | 10:56 AM
  #6  
koreanpers's Avatar
Member
 
Joined: Sep 2005
Posts: 237
Likes: 1
S500
are you talking about the interior fan inside the cabin??? or outside near the radiator? my interior fan would squeel sometimes. It seemed like when it was cold outside it would do it more...then eventually it would go away. it was the bearings in the interior cabin fan that went bad but starmark war covered it
Reply
Old Jul 3, 2007 | 01:39 PM
  #7  
NazarKmet's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2007
Posts: 22
Likes: 0
2010 Mercedes S400
Thank you.

This is sound like a bearing i looking for them if you have any sites available please post it Thank you.
Reply
Old Jul 8, 2007 | 11:36 AM
  #8  
koreanpers's Avatar
Member
 
Joined: Sep 2005
Posts: 237
Likes: 1
S500
Originally Posted by NazarKmet
This is sound like a bearing i looking for them if you have any sites available please post it Thank you.
? sites? well, i just took it to the dealer and they diagnosed and replaced.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 05:26 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
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.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE