mirousse

I just came back from a 3 hour road trip. The fuel pump started buzzing, steady, for the last 40 minutes. Appart from the noise, everything was fine. All the horses were there and healthy!

Thereafter I had let the car cool down in the driveway for an hour or so and I started it again...the buzz was gone.

Is it a sign that the pump is starting to fail?

Does a fuel pump fail suddently or does it show signs of weakness before giving up?

Should I start looking for a replacement?

Cheers.

Michel

89 928 S4 ROW

leperboy

This is what mine did. It buzzed when warm when it was failing. It failed me once and I had never paid attention to it before that failure. Once it did, I began to notice the buzzing.

I suspect it is starting to go and they can go intermittently or slowly, or all at once. I think it's worth changing before it strands you.

Matt

andy-gts

I only know on a chevy that sounds like replacement time

Landseer

If you reverse it into a container you will probably clear any crap that is inside it.
This needs to done carefully so you don't detonate you and your surroundings.

mirousse

You mean reverse the polarity and have the fuel go the other way? Can it do that? ... Or just remove it and turn it upside down to remove any foreign stuff?

AO

it can do that.... be careful.

robot808

Listen to Andrew, he is sexy hot.

Sailmed

Or just cut and twist the wires....
Job security....

AO

Oh Bob... stop! I'll spontaneously combust!

Mrmerlin

sometimes the pump can make a buzzing noise thats louder than what you might usually hear.
This is due to the fuel getting warm/hot the normal way to keep the fuel cool is to run the AC system as there is a provision for the fuel to run through the AC fuel cooler this lets the return fuel be cooler when its returned to the tank.
The other way to cool off the fuel is to fill the tank usually the new fuel will be closer to room temperature.
It is also a good idea to add a few OZ of Marvel Mystery oil to the fuel this keeps the pump and injectors lubed .
I have put new pumps in and they will after running on hot fuel make quite a bit of noise, unless you have other indications of a failing pump , besides the noise, it should be fine, if after things cool off it returns to quieter condition

mirousse

Mrmerlin,

I normally use the car on short 25 minute drive to go to work. Today was a longer drive ending up into a 45 minute trafic jam. The buzz started into it. It went away after the car has cooled down (it's 32F up here!). Your explanation makes sense.

My understanding is that the fuel goes to some kind of integrated fuel cooler in the A/C and back to the tank, correct?

As for the MMV..I'm a fan!

pewter82

Change it out, definately not worth the frustration of it failing. I had one fail on a S4, never again.

jason

83 S

the flyin' scotsman

Michel..............at our current Canadian temps the fuel is not getting warm..........the pump is.

My fuel pump does same, makes a buzzing sound after being run for over an hour. Is silent when cold.
I've never had an issue but could be on borrowed time. The fuel filter has been changed as has the connecting pipe and pressure valve so I've nothing else to change but the pump.

I'd like to hear other inputs.................BTW my car is a '88 S4 with no intank pump.

mirousse

Thanks Malcolm...what's the temperature like these days in the West? Any snow so far?

David L. Lutz

In my experience when you touch a live wire to the terminal to run the pump backwards it usually gives off a spark . . . not good near gasoline