I'm getting this squeaking/squealing noise when I turn on my climate control system. It sounds mechanical and goes away after about 5 seconds. A friend of mine with a CL Class said he had the same issue and it turned out to be an 'aspirator' unit needing replacement. I think he said they just replace that whole control unit. Anybody else have a similar issue with their E at some point?

 

Blower Fan? Mine failed at 78,000

 

Is it a whistling type of noise, that sounds like it is originating from the from vents?

 

I can hear the whispling noise (sounds like a cricket), lasting a few seconds for every minute or so, from the vents when the fans are turned on. Putting my ear near the glove compartment, i can hear that's where the noise is originated from. My guess is that the bearing on motor fan is wearing out. Maybe a new fan is needed or applying some lube on the bearing (if there's access to that).

 

There must be some obscure plant in a far away location that pumps these things out for the auto industry. I had one fail on a Japanese car and I tried lubricating it to no avail. They are pressed and stamped together and I don't think a full blown machine shop could get one apart to service it. Whether it is a Yogo or a Rolls, they all same to have the same crappy design / parts.

 

If I remember correct access to the fan is through the glove box.

I would not waste my time trying to lube it. Too much work and it will only fail soon after. Buy a new one. Right same crappy design as others, probably generic supplier.

 

[QUOTE=vettdvr;3857721]If I remember correct access to the fan is through the glove box.

QUOTE]

Correct. The fan is under the glove box. To access it, just need to remove the bottom panel under the glove box. The motor blower resistor, which often goes bad after ~100k mi, is also right next to the fan. When my car had 50k mi, this whispling noise only happened a few times a day, now at 66k mi, this noise comes & goes every minute. It's getting annoying. I'll probably replace the fan during the Christmas break; should be an easy DIY.

 

Yah mine sounds like a squeaky hamster exercise wheel coming from the vents. It only happens for a few seconds when I first turn on the climate control. Since I am still under CPO I think I'll make an appt with the Stealer. These Black Forest cars sure have alot of character. But they drive great.

 

Dealer replaced fan motor under CPO warranty while I had it in for the transmission valve body replacement. The CPO warranty is a MUST!!

 

I thought about trying to get my fan motor replaced under my CPO warranty but the fan only makes the noise in the cold weather and then only a couple minutes until the car warms up. So, it's not too bad. Unfortunately, my CPO warranty expires tomorrow.......it's been great.........so when the fan eventually fails, I'll have to pay for the repair or DIY. Sounds like it might not be a difficult repair that would definitely save big bucks!

 

I just got my car back from the dealership not too long ago for a A/C Compressor Pulley replacement (loud RPM dependent engine whining) and only just started to notice this intermittent slight chirping (crickets?) sound as well. It does seem temperature dependent. Annoyingly it rears its head at almost precisely the same points on my daily morning commute (also engine load dependent?)

So you guys are definitely not alone. Its good to know which general direction I can point my trusted SA's attention to - saves time. A big thanks to all who shared.

 

Don't forget to check the belt idle pulley. It is the small one and fails frequently due to high loads and RPM. They are about $20 in the box.

 

I have found so much useful info on this bord, I decided to document this fairly simple repair in appreciation of all those who have gone before me.
This was documented on our 2003 E 320 with ANALOG controls

First, remove the front passenger floor mat and get something to cushion your knees. If over 40, go ahead and take some Aleve.

You will need a few tools (image 055)

I used a #25 torx bit to remove the panel (image 54) that is held by two machine screws. It is accessible directly beneath the glove box. There is a built in duct that directs air to your feet, care in removing it by flexing it slightly . It was somewhat difficult to re- install. Note that the cover square duct goes OVER (outside) of the dampered portion of the heater duct. There is one friction plug as well as the two screws. There is a plug that powers the lamp, pinch and tug gently to disconnect.

Now we have exposed the bottom of the fan compartment (image 053)

There are 4 torx screws that need a #20 bit. Three are deep in plastic wells and are not visible. You must feel for the bit to engage and turn them cw.
The one in the rear that is surface visible required a short shank #20 torx bit and a 1/4 in drive because of clearance to the floorboard. These are a ***** to put back. You need either a magnetic tip or a telescoping sleeve used with battery drills to support the screw while you bullseye it blindly in the recessed hole. Scotch tape did not work for me.

You should be able to "crack" the bottom cover Slide it carefully along the wire and expose the plug on the bottom of the speed controller. Pinch it hard and gently tug. The fan is now free of encumberances save the 4 screws.

There are 4 each #20 torx screws that hold the fan inside of the scroll cage.
Support the fan with your hand or a short stick and remove all four screws.

Your fan should look like image 046.

Image 038 shows empty scroll cage after fan is removed.

Remove the fan speed controller (two #20 torx) and fan power plug (same drill, pinch and tug gently)

Your old fan should now look like image 043.

Now reattch the controller to the new unit. Should look like image 046 again.

Insert the fan/ controller back into the void scroll cage.

You must hold the fan with one hand and insert at least two screws hand tight before allowing it to hang. Install the two remaining screws and tighten all. Attch plug back into controller

Reinstall the fan compartment cover with the three deep well screws and one surface mount- image 053. Reinstall wire in two plastic looms

Reinstall large knee cover with two machine screws #25 torx and make sure the duct is engaged. Screws won't align unless it is correct.

Test motor. Annoying squeak is gone for a few more years.

 

Thank you very much for the great write up. Would you happen to have part # for the new fan?

 

Motor is part #2118300908 (for comparison shopping parts.com $184), regulator if needed 2308216451 (173.65)

 

I am still waiting to get mine done. Man.. should we file a complain regarding that cheap fan?

 

I got mine at "Auto Parts Warehouse"

It was 124.95 and the complete unit with the controller was about $212???

They have an old part number and MB has a new number. I wish I thought there was an improvement but I don't. Maybe the OEM part is improved

Two interesting facts,
1. The replacement fan had a mark near the BEHR logo that looked like it had been purposefully disfigured. When I pulled the OEM unit imagine my surprise when the three point star occupied that exact position in the mold.
2. There really is no way to service the old one. I tried to salvage the squirrel cage and I could not even get it off the shaft. About a table spoonful of graphite or carbon spilled out onto my kitchen table and the shaft had moved about 1/2 inch in the windings so I am pretty sure that beating on it toasted the brushes / windings/armature. I threw it in the garbage (a rare event with my parts). I still have some worn out stuff for a BMW that is probably in the crusher.
It was a real pain to get into the floorboard and service this thing. Many might consider $100 bucks in labor a deal. Push the passenger seat all the way to the rear and give it your best shot.

I agree that it is a POS. I have replaced one in another vehicle already so it is not just MB. In the 1950's that motor would have had 4 long skinny bolts that held the motor windings / brushes together and Timken or somebody would have sold you a new bearing for $1.00.
Not only is it a hole in your pocket, it is a tremendous waste of resources.
BTW, ALL SCREWS ARE RIGHTY TIGHTY . My previous post contained an error
I am sure that my age is telling on me.

 

Great info and write up.

Mine makes the same squeaking sound, but only at low fan speed.

I also have an odd phenomena of the rear vents not blowing very hard. I might even say, no air is coming out of the B-pillar or rear console vents. I should also note that air doesn't really blow hard out of the bottom (footwell) vents either.

And now that it's hovering in the single digits, temp wise, I can fell a cold draft coming around the parking brake area at highway speeds.

Any ideas on these oddities?

**EDIT**

I should also mention that every time I drive the car, at some point in the drive, I hear what sounds like a flap closing. It appears to be coming from behind the passenger's side of the dashboard. There's no pattern of when it happens. Sometimes 5 minutes into my drive, sometimes 1 hour.

However, there is no difference in airflow before or after I hear this flap sound.

 

I would not try to lubricate the old fan as I gave it a shot and it helped for a couple a months but then it was back. It was almost worse than before i messed with it! furthermore after I lubricated it, to times the fan would completely stop for a some minutes (to much oil) I ordered a new one from BEHR and it works perfect and have not had any issues so far.

 

Thank you Clinton Horn for the detailed instructions. Got my squeaky motor changed out in less than an hour. Magnetic tip Torx made installation of screws a breeze. The real time saver was having all the right toosl assembled before I got started - your list made that easy.

 

KL2DC-I have an RPM dependent buzz from the vents on occasion. Is that what yours was like? If I shut off the fan, mine stops altogether, and I am not sure that would be the case if my problem were a pulley. Every time I ask about it at the dealer, they are unable to replicate it.

 

Mine only made the noise when the fan was at idle speed. So that may by why yours happens near the same spot in your commute. By hitting off/on on the Climate Control the noise would turn off/on. Sounds like a weak cricket.

 

I followed Clinton Horn's instructions above and the job went very well. About an hour of work and it saved me $900. I bought a replacement blower assembly from Amazon and it was only $85! Better yet, it was a Bosch part with a Mercedes logo on the tag. I have a 2008 with an iPod connector in the glove box so there was one more connector I had to disconnect, but this was pretty easy as well. If you have one, slide down gray part of connector (away from attached cable) and the plug pulls right out. The chirping has gone away. The old part did have oxidation at the top of the axle so I'm guessing water corroded the bearings. May be a bad design if this many people have issues with it. Bottom line, don't pay someone $1000 to do this if you have an hour to spare.

 

If lubricating the motor I would recommend tranny fluid.

 

Thanks for the information I was able to change out the air blower motor in 40 minutes.