Vacuum Problem
 

When I get into my 83 300D Turbodiesel and start the car, I get a high pitched (but low volume) sound coming from the driver's side dash area.

Once all the doors unlock, the sound goes away. The same sound when I lock the driver's side door and goes away when all the doors lock.

My guess is that I am having a vacuum leak somewhere. My door actuators r fine and hold vacuum.

Some others have posted similar problem but no one seems to have encountered this issue.

What would cause this to occur ?

Has anyone else encountered this problem ?

vacuum
 

Do your door locks still work in morning? If it is loosing vacuum, they probrably won't all unlock.

The doors unlock after I start the car. But the same sound occurs when, after driving around, and the locking the doors.

There seems to be some unit under the dash that may leak. Some other forum members also have experienced such a low pitch sound that comes from under the dash.


It stops once all the doors have unlocked or locked?


I agree it some vacuum leak. It is not in the door circuit or the vacuum resevoir in the trunk.

Does someone have a vacuum diagram for the central locking system ? Seems to me the problem lies in the cabin.