Noisy central locking - W202
 

Hello, all,

I've done a search on this topic for the W202, and it seems earlier posters have had a slightly different problem from mine.

The locks on my '97 C230 work fine, both locking and unlocking. However, in the last month or so, when I lock or unlock the doors (either with the key fob, a key in the passenger door lock, or via the dash switch), I hear a fairly loud "thuttering" sound which appears to come from the passenger side rear door. Behind this, I know, is where the vacuum pump is located. However, unlike the other posts I've read, the vacuum pump does not keep on running after the doors are locked/unlocked.

Is this a sign of trouble to come? Rubber seals going? How can I get to the vacuum pump, and what do I look for (yellow hoses are the ones for the pump, right)?

TIA,

kind of coincidental but I had the same kind of problem on my `98 202 a few weeks ago.
The problem went away and I am not sure why, but what I did do is lubricate the locking pin for the fuel filler door with 303 rubber protectant. I sprayed lots of 303 around that fuel filler lock near the gas cap and it helped me

test to see if the noise is from the fuel filler door lock.

Ethan,

Great idea. Excuse me while I smack my forehead for not thinking of it!

To reach the locking pin, do I have to remove part of the trunk liner, or could I reach it from outside, i.e., through the fuel filler door?
.

do it from the outside, just open the gas filler door and spray away, as I recall there is a rubber gaiter at the base of the locking pin, I saturated that with 303 along with the rubber surround of the gas filler tube and the groaning noise I was getting went away. Of course I had my gas cap tightly on.

Hope it works for you.

i have the exact same problem on my merc c200 w202 1997 car.

i will use wd40 lubricant spray that we get here in the u.k. to see if it cures the problem and post the resutlt on here

WD40 isn't a good lubricant it is more of a cleaner. I don't think WD40 will help rubber on the long run either.

Glycerin rubbed on would probably be better.

Let us know what happens

i have also got something called white lube in a spray can.

i will use this and see if it helps

it is freezing withbelow zero temps and dense fog here in england.

i sprayed white lub spray into the hole where the central lock mechasim comes out of filler cap area.

no difference noted,so i will now try to operate the central lock with the fuel filler flap open so that i can see the rod that comes out the litttle hole and try to lubricate that.

I had a look with the fuel flap open and lo and behold the lock rod does not come out from the little hole!!
You hear a "thuttering" kind of noise but the flap ddoes not lock-i gues u learn something new each day-no amount of white lube,wd40 or glycerine would have fixed this-so i guess i will have to remove the trunk liner to gain accesss to the fuel cap actuator and lock mecahanism to investigate further.

since it is freezing and foggy,i will leave this till the new year when the weather is better and report back later.

does anyone know how to remove the trunklid liner to get access to the central locking actuator mecahism for the fuel filler flap?


how easy is it?.

Easy, but you should use a trim puller - a plastic or metal flat piece with a Y shaped cutout - that slides under the plastic button fasteners to pop them off.

Remove the floor carpeting, it just pulls out and remove the button fasteners on the side trim, you could probably just need to pop the top buttons to access the pump area.

#

thanks for the advice as above.

i managed to bet behind the liner and did not have to remove it completely.
when i put my hand in to locate the fuel flap central locking actuator i found that is was hanging loose from its holding bracket.

i fitted it back and now the fuel flap cover locks and unlocks via the central locking!:D