Rear Noise when shifter not in Park

[daazn1]

Hi Everyone,

New owner of W202. Brother didn't want his C280 anymore and gave it to me.

I hear a strange, intermittent buzzing noise coming from the rear of the car. At first, I thought it was the antenna motor going bad.

I've done a search but did not find anything specific to this noise.

Facing the rear of the car, the noise is coming from near the right tail light. I pulled back the interior covering near where you change the light bulb for the tail light and the noise is definitely louder in that area. What I see are 2 tubes a yellow and a white tube that also vibrate with the buzzing.

When shifter is in PARK, the noise goes away. When in any other gear, it starts up again.

Any information anyone can provide is greatly appreciated.

Tom

[tpliquid]

Originally posted by daazn1
Hi Everyone,

New owner of W202. Brother didn't want his C280 anymore and gave it to me.

I hear a strange, intermittent buzzing noise coming from the rear of the car. At first, I thought it was the antenna motor going bad.

I've done a search but did not find anything specific to this noise.

Facing the rear of the car, the noise is coming from near the right tail light. I pulled back the interior covering near where you change the light bulb for the tail light and the noise is definitely louder in that area. What I see are 2 tubes a yellow and a white tube that also vibrate with the buzzing.

When shifter is in PARK, the noise goes away. When in any other gear, it starts up again.



Any information anyone can provide is greatly appreciated.

Tom


post videos

[htfan1]

Sounds like it could be vacuum pump noise. You may have a pump issue or a vacuum leak somewhere. Those yellow tubes are vacuum lines.

[benzonline]

Does it go on and off and make more of a humming/buzzing noise?

My freinds C220 did this then one day the door locks didnt lock anymore themselves...aswell at that point the buzzing/humming stopped.

[daazn1]

Happy Thanksgiving.

Yes it does come on for about 2 seconds, then off for like 5-10 sec. then on again. The interval between the time it comes on varies. It will come on when its in drive/reverse but not in park which is strange.

How long before it stopped in the C220? Is the vacuum line related to the use/operation of the door locks? Thanks for your input.

I'll try to play with the door locks when I get the car back from the tire place (getting new tires) and see if it has any effect.

I'm not technical enough to do digital video but would some pictures help as to the general area where its is coming from?

Thanks very much for your help.
Tom

[alphanumeric]

my 2000 c230k does the same freaking thing!!!! but when I throw it in park it goes away.. I thought it sounded like a fuel pump or something.. dunno.. I dont worry about it anymore..

[benzonline]

It did it for about a yr and then the motor burned out finally.

[htfan1]

Originally posted by daazn1
Happy Thanksgiving.

Yes it does come on for about 2 seconds, then off for like 5-10 sec. then on again. The interval between the time it comes on varies. It will come on when its in drive/reverse but not in park which is strange.

How long before it stopped in the C220? Is the vacuum line related to the use/operation of the door locks? Thanks for your input.

I'll try to play with the door locks when I get the car back from the tire place (getting new tires) and see if it has any effect.

I'm not technical enough to do digital video but would some pictures help as to the general area where its is coming from?

Thanks very much for your help.
Tom

I'm still having the problem in my C220. It only occurs when the car is in a driving gear. (No pump noise in park. Must be engineered to enable pump only when moving.) It will buzz/whurr for the first few minutes of driving, then quiet down. It impacts my center AC/Heat vent functionality which is also vacuum control (search for post) like door locks.

My local shop knew exactly what it was. A Vacuum leak! By where??? I haven't spent the $$$$ to have it fixed yet.

[daazn1]

Great. Thanks for the replies. I'm glad that I'm not the only one. But its unfortunate that it seems common. I'll call up the local shop Monday and ask how much to fix the vacuum leak. Its seems like it could be a pain to track down. I'll let you know what I get quoted.

Cheers!
Tom

[benzonline]

How do these leaks occur and how should I prevent it?

[htfan1]

Originally posted by benzonline
How do these leaks occur and how should I prevent it?

If you could find someone that knows the answer, we'd all be very happy!