380sl bussing sund from rear end when car is running

[pnewman]

I amy getting a Bussing sound from the Rear end when It's running. I think it's comming from the Gas pump and filter. Does amy body know what this is

Thanks Pete

[yeldogt]

Fuel pump. Mine has always been audible.


Is this a new noise?

[pnewman]

Yes

[yeldogt]

Sometimes I hear the pump more than at other times -- and it can be quite loud. Not knowing how long you have owned the car and obviously not being able to hear the sound puts me at a disadvantage.

Not much in that area to make any noise -- you can have vibrations from the exhaust system when the rubber mounts fail but they tend to be more of a "clunk a clunk" then a buzz.

The fuel pump will run for a moment when you turn on the key before you start the car -- do that and see if that is the same sound

[pnewman]

This is what I know. I have owner the car for four + years. I had the fule pump replaced two year ago when the replace all the rubber around the muffler.It was running ok till yesterday. I don't here anything when I first start it up it's when I run it for a while that when I hear it

[yeldogt]

The different 107's I have owned all had loud pumps -- I have never had one fail. It is always possible that the replacement is failing - not much you can do about it.

Mine is more noticeable when the tank has less fuel in it.

Normally a hum sound but occasionally a buzz especially after driving it for a while in hot weather.


We are talking about a standing situation ? -- not while the car is in motion.

[rocky raccoon]

Pete:
The entire fuel delivery assembly (pumps, filter, non-return valve) is mounted to the chassis by rubber vibration isolaters. When your pump was replaced, did they also replace those rubber mounts? If not, and there is considerable mileage and age on the car, that could be the source of your noise.

Once it starts, does the buzz persist when the car is idling or at a high idle out of gear? If it does I would suggest getting under the car and looking for the source. Have a friend press the accelerator while you look, listen and feel. Does putting your hand on the fuel assemby stop the buzz or change it?

Don't let your friend run over your head.

Regards; another Pete