Ok, I need some help I have '89 560sel. I have a weird noise coming from my fuel pump not the regular noise,, ( i know that the fuel pump is supposed to make some noise) this noise can be heard in the cabin and its kind of like a bee buzzing but it buzzes stops for a sec and buzzes a little some more. I cant really explain how it sounds. I am wondering what can be wrong with my fuel pump and also where is the cheapest place that I can find a fuel pump and how much will it cost.

Thanks alot in advance,

i have the same problem on my 190e -1.8 litre uk spec car.
sometimes the buzzing from the fuel pump is hardly audible in the car and yet at other times the buzzing gets very loud and is heard inside the car-i have had the fuel filter replaced a year ago,when the car had a full 108,000 mile service,

my question is what is the cause for this behaviour?is it a fuel pump nearing the end of its life or blocked injectors?
could it be a faulty charcoal cannister which i have not replaced at 72,000 miles?

otherwise the car is as smooth as ever and starts up well.

may be the moderator or techs will shed some light on this issue.

Hi pilot,
I just changed my fuel pumps on a 1987 420 because of a leak rather than noise.
If you do a search you can find the pictures I took of the area.
The pumps should be at the passenger side rear between the wheel and the differential.
I would go under there with the car in idle and listen or touch to feel for vibration to see which one is making the noise.
Fuel pumps at FastLane are about $202 and each comes with a new check valve.
Somewhere I read to also change the fuel filter when replacing a pump.
Good luck.
Reinhard Kreutzer

The fuel pump(s) can be noisy and still be OK. Check the current draw(this can be done at the FP relay). This will tell you if one of the pumps is having a hard time turning. If the current draw is OK(I'm not sure, I think it's about 8A) and system pressure is good, make sure the mounts at the pump package are OK. Also, I seem to remember seeing a car or two in the past that had one of the fuel lines touching the pump. This can transmit noise into the car. Good luck

Not to dismiss the fuel pumps, but a leak in the locking system can cycle the vacuum pump on and off. The vacuum pump will also sounds a little like a bee buzzing when it is cycling.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

thanks alot for all your help im gonna check everything out tomorrow and probably will order the new fuel pump.