Clunking noise from passenger air vent on startup

[Wabby]

Anybody any suggestions before I throw it back @ the dealer to look at?

2017 c250d coupe.

When start the car, and start moving, I get what sounds like a motor trying to move something quiet loudly coming from the passenger vent (nearest the door).

After 10 seconds or so, it stops and is fine.

Air comes out. The knob twists and shuts airflow off.

Don't really want to hand my new car back to them to look into if its something I can possible do without damaging ****?

 

[brucemillar]

This sounds like he 'dreaded' blend flaps issue where either the bland flap gearing has broken or the gearing/motor has lost its register position. The clonking you can hear is the motor attempting to calibrate the flaps to the ECU on startup.

Back to the dealer, if I were you. On older cars this this can be, a massively expensive fix +£900 as it often is a dashboard out job.

 

[Wabby]

Well, it went in yesterday for service and I got them to have a look at this.

They put some 'special lubricant' on it and apparently it won't happen any more.

We shall see.

On another note, I found out the reason that the wing mirrors 'park' in a different position is because their are 2 inches difference in length between the drivers and passenger mirror. WOW.

 

[CaptainChaos]

Mine clonks and grinds too. I will be requesting some of that special lubricant you mention.


(Then I'll see about getting my air vent mended).

 

[Wabby]

Meh ... Noise is back.

Nice and quiet whilst it lasted (just over a week).

Looks like I'm dropping it back off ...

 

[markjay]

On my W203, there used to be a reset procedure for the aircon.... initiated by some sequence of button press. It might not be the solution to this particular priblem, but it's worth Googling to see if there's a similar thing for your car.

 

[Wabby]

Yeah, I was looking at this but one of the buttons for the reset appears to no longer be on the dash

Any no procedure for my 205 either

 

[redjules51]

Well, it went in yesterday for service and I got them to have a look at this.

They put some 'special lubricant' on it and apparently it won't happen any more.

We shall see.

On another note, I found out the reason that the wing mirrors 'park' in a different position is because their are 2 inches difference in length between the drivers and passenger mirror. WOW.

Shame they didn't put some Pixie Dust on at the same time I've heard that helps enormously along with copius amounts of Bullsh*t

 

[Petrol Pete]

Well, it went in yesterday for service and I got them to have a look at this.

They put some 'special lubricant' on it and apparently it won't happen any more.

We shall see.

On another note, I found out the reason that the wing mirrors 'park' in a different position is because their are 2 inches difference in length between the drivers and passenger mirror. WOW.

No they didn't, it would have taken hours of labour just to get to the servo activators. This is not going to go away and will only get worse. Plenty online about this , MB changed the design of the activator arms to make them stronger, they are cheap to buy but very expensive to get to in terms of workshop hours.

Good luck.

 

[Petrol Pete]

Plug in a OBD reader and you will probably see "M2/15 left and right footwell flaps actuator is stiff or blocked" or similar.

 

[Petrol Pete]

Having said that the car is practically brand new and I would hope MB changed the design and this is something else.

 

[Wabby]

Having said that the car is practically brand new and I would hope MB changed the design and this is something else.

I was hoping they had changed the design tbh .... But its back within 10 days of it being 'lubed' so I shall be going back .....

 

[Wabby]

Well after multiple ‘lubes’ its still present so its dash out next week and invasive surgery.

On a other note I quiet like the petrol engine in the c200 cab they have loaned me. Shame the rear srats dont fit my child seat in though. This one also has the vent noise .....

 

[stephenmercedes]

They put some 'special lubricant' on it and apparently it won't happen any more.

WD40, available everywhere, not that special LOL