W202: Debris in vent, left of cabin filter (?).

[MarkC]

I have a 98' C-class and recently replaced the cabin air filter. The blower motor is under/behind the glove box with the filter to the left of it, toward the center consol.

While replacing the cabin air filter I noticed leaves and debris in the vents, left of the cabin filter. This, and the thought that filtered air should flow through the blower motor, and not dirty outside air, got me to question which way the air actually flows.

Does outside air first pass through the blower motor before being filtered? And why would there be leaves and debris, in the vent left of the filter, with leaves and debris on that side of the filter (the side that faces the cleaned air)?

TIA
MarkC

[MarkC]

Does anyone know?

[jlomon]

I don't know with 100% certainty, but I'm pretty sure that the air passes throught the blower motor before the filter. My reasoning for this is because when I have removed my blower motor assembly to lubricate the fan due to it squeaking, there was a bit of debris in the fan area. Stuff like little pieces of leaves. This debris was way too large to have passed through the cabin filter only to get stuck in the blower fan, so it must have come from the air inlet that feeds the system.

I can't remember from the last time I changed my cabin filter, but what side of the filter was clogged with debris when you removed it? If it was the side of the filter that is closer to the fan, as opposed to the side that is closer to your climate control unit on the centre stack, then that's the side that the air enters the system from.

If you want to clean out your blower motor, its an easy job. It takes around 20 minutes to remove and replace, and the only specialized tool you'll need are torx head bits for a couple of the screws. The access panel is just to the right of your cabin air filter.

[MarkC]

Thanks for the reply. There were leaves and debris on the climate control side, which had me a bit confused. On another note, the blower motor is vibrating which I can feel through the steering wheel and dash as the fan speed is increased, so I'll likely have to replace it soon.
Thanks
MarkC

[Ebony905]

I can not seem it fine any answer to this. Is there a Cabin filter motor and A
Climite control Blower motor also ? If so were is the Cabin filter motor? Everytime
I use the Radio I can hear a swine and it loudler when I speed up and it get lower when I slow down. I have removed the climite motor and lub it up it works
fine now? I have a 93 500SEL
Thanks

[jlomon]

Hi Ebony905,

I don't think your problem is related to the blower motor. If you hear it when you're using the radio, and the pitch of the "whine" changes with engine speed, I think you're getting radio interference from your spark plug wires. I'm not a tech, so don't go out and buy new wires just because I said so. Do a search on "radio interference" and see what comes up first. But I bet that is where your problem is.

Jonathan

[MarkC]

Originally Posted by MarkC

... On another note, the blower motor is vibrating which I can feel through the steering wheel and dash as the fan speed is increased, so I'll likely have to replace it soon.
Thanks
MarkC

To update this thread, I did remove the blower motor where I discovered a piece of plastic (the cut off end of a chalking tube) lodged in the turbine which caused the vibration. The fan runs normal and smooth now it‘s removed.
Thanks, MarkC