C280 making loud humming noises from the vents. - PeachParts Mercedes-Benz Forum

C280 Sport · #1 01-09-2009, 01:54 PM

C280 while driving it the AC/HEAT system makes a loud humming noise. Almost like the fan needs to be oiled or something. When I hit the breaks it noise stops but when i let my foot off the break it humms again

. This is very weird. Also it does it when the fan speed is on very low also. I look around and couldn't find any answers. Any suggestions would be great thank you.

mpolli · #2 01-09-2009, 02:45 PM

You might inspect the cabin filter.

C280 Sport · #3 01-09-2009, 03:05 PM

Had the cabin filter changed 2 weeks ago. Any other possile things?

dpkreuze · #4 01-09-2009, 03:13 PM

Water, leaves, mice, seeds, dog food, all have been found in the blower housing.

C280 Sport · #5 01-09-2009, 03:56 PM

Quote:

Originally Posted by dpkreuze

Water, leaves, mice, seeds, dog food, all have been found in the blower housing.

Well here is this thing. I took out the glove compartment and checked the filter and found nothing. Looks clear and clean. But I dont know how to get to the blower. I know I am really close to it. But yet I am so far away from finding this issue that has drove me nuts since day one

Ethan · #6 01-09-2009, 05:18 PM

The blower is situated above and to the right of the cabin filter. you push aside a wiring-loom. slide some white fasteners on the edges of a black panel, and remove the blower with maybe five or six torx(I think) screws.

In the eleven years I've had my C230 I've had to clean the blower three or four times to get rid of a noise caused by debris.

Does the noise change as you change FAN speed? if the frequency changes with fan speed then you know it's the blower.

C280 Sport · #7 01-09-2009, 07:01 PM

You can onlu hear it when it is on low. You can hear it a little bit when its on high. Its still the same noise you can only hear it more when the fan is on low. Also it does it when going aound a corner and turring to the right.

Ethan · #8 01-09-2009, 07:35 PM

from your description it could be drivetrain or brakes, but the fan blower seems like a good start, once you get into the blower you can clean out the ducting with some Lysol and really treat the HVAC.

C280 Sport · #9 01-10-2009, 10:47 AM

[quote=Ethan;2073671]from your description it could be drivetrain or brakes quote]

How could it be the drivetrain or brakes?

Ethan · #10 01-10-2009, 01:12 PM

it's hard to diagnose sound issues on a forum. when I read your post I'm not reading anything about not hearing the sound when the HVAC system is turned off.

also you say you hear the whine when driving and a HVAC blower issue should be apparent when the car is stopped. Of course air flow when moving could move debris into the path of the blower fan.

I just don't want to convey as a fact that it is your blower motor.

I hope you post some more information and let us know how things go so we can fix it.

C280 Sport · #11 01-10-2009, 04:51 PM

Quote:

Originally Posted by Ethan

it's hard to diagnose sound issues on a forum. when I read your post I'm not reading anything about not hearing the sound when the HVAC system is turned off.

also you say you hear the whine when driving and a HVAC blower issue should be apparent when the car is stopped. Of course air flow when moving could move debris into the path of the blower fan.

I just don't want to convey as a fact that it is your blower motor.

I hope you post some more information and let us know how things go so we can fix it.

Ok update time. There is no noise comming from the system when it is shut off. But when it is turned on it starts with the noise and then goes away. Start driving it goes away untill you come to a stop then it starts again but while hitting the brreaks

. Take a corner to the right and at about half way for a first turn it comes on again

. This is one of those weird issues. Its got to be the blower I would guess

C280 Sport · #12 01-15-2009, 06:22 PM

Well I had the shop take a look at it while doing my Service A today. They found nothing. Time to take a look myself I guees. I will try Lubing it like BOBS said.

mpolli · #13 01-15-2009, 11:15 PM

Quote:

Originally Posted by C280 Sport

Well I had the shop take a look at it while doing my Service A today. They found nothing. Time to take a look myself I guees. I will try Lubing it like BOBS said.

Where did they look? Did they take the blower out?

C280 Sport · #14 01-18-2009, 12:02 AM

Quote:

Originally Posted by mpolli

Where did they look? Did they take the blower out?

They told me when they took it in that they drove it around and it did not make any noises. I will do it mysel because it has made that noise many times before. How do I access the Blower Motor?

ScottyP · #15 01-15-2009, 06:36 PM

Ive also experienced this problem.

Remove the fan and vacuum the entire blower basket. Also vacuum up all debris in the blower opening. You will probably find dead leaves & little pieces of branches (from parking under trees). Vacuum the vent duct as far as you can reach throughly.

Oil the blower bearings & spin it by hand a few times. Then reinstall.

I found probably 40 dead leaves and many small little branch pieces in my fan basket. One of the small pieces of wood was causing noise when spinning a low speeds.