Ok, I haven't found anyone asking this so here goes...

I have a C280/300 and every now and then I can hear what appears to be a spring stretching noise, like a vent ahead of the front passenger either shutting or opening. Occasionally, after unlocking the door and getting in the car, I can hear like a electric motor buzzing as though it is turning something, initially I thought this was the side mirror unfolding from it's parked position, but they are already unfolded by that time. All these sounds are around the front passenger side.

If it is a ventilation thing, where would be the obvious place to look? I have taken the cover off where the cabin filter is, but can't see vents there.

Any thoughts would be appreciated! Thanks!

 

Completely normal and intended. There are louvers/dampers in the vents. I recall being able to see them open by shining a flashlight down the center vents and then turning the key to ACC position. I discovered this when cleaning out the vents/AC w/ Klima Kleen, which required the tube to be inserted as far down the vents as possible.

 

Thanks, I don't mind the whirring noise of the vents but the light clanking noise of the springs is a little annoying. Would you know a way to get to it to dampen it down? The noise seems to be from under the dash rather than through the center vents though....

 

Clanking sounds are def not normal. The slight whirring/closing sounds are noticeable, but def not anything like metal on metal. Also, they don't emanate from under the dash either, like your situation so I don't know what else it could be.

 

No, this is normal. I just think the OP is over exaggerating the "clank" or clunking of the noise. If its quiet, like nighttime and you just turn the car on or off, the air vents will open/close accordingly. Personally, I like the noise, and it reminds me of the differences you get in a mercedes-benz versus a $10,000 hyundai...

 

LOL! No, I can certainly put up with whirring noise, but I do also have the light clanking which is definitely the sound of the spring stretching. The spring must be touching something else to make that noise. i just need to know how to get to it. There must be a diagram of the ventilation system somewhere.....

I'm sure a $10k Hyundai wouldn't have that noise!