noisy,buzzing fuel pump-190e

[sunil190e-1.8]

the car is a 190e-1.8 litre with 113k miles on the clock.

lately,i have noticed the electric fuel pump to be more noisier than usual.

this in intermittent,sometimes it is really loud and can be heard in the car and then at other times it is hardly audible .

any ideas on what is the cause for this behaviour?

i had the fuel filter replaced at 108k miles.

the car starts and drives normally.

[xp190]

noisy fuel pump usually means that it's wearing out and will have to be replaced soon.

I even heard that from the time it starts buzzing like that it's about four months until it is gone completely, but I guess that depends on how often you drive and many many other things.

xp

On my friend's 124, I saw the same symptoms and had him swap out the fuel pump.

After that, the it was business as usual...

Only the regular faint buzzing of the fuel pump is now heard, nothing loud.

My 2 cents...

Azhari
Babybenz 1991 190e 1.8

[richunters]

Would a buzzing fuel pump give any other indication/warning before it fails? Mine has been buzzing (89 300SE) for awhile, but was told by the mechanic that the buzzing could go on for years. But sure hate to get stuck on the road when it finally goes.

[Mike Richards]

The single pump in my 126 car has been buzzing on and off since I bought it in 1997. Some days it's worse than others.

I'm not convinced that a buzzing sound is indicative of imminent failure.

[sunil190e-1.8]

thanks, mike, for your input.

i have also read on a uk merc website that intermittent loud buzzing is not a problem as long as it does not groan loudly or if it appears to be definite straining noise.

this information came from a reputable independent benz repair shop owner.

so,i am going to turn up the volume on the radio and forget about the buzzing!!

[fz500sel]

I concur that the buzzing fuel pump doesnt mean that it is goin'. After reading about this on this website I noticed that mine was buzzing. I said to myself that down the road I will need to replace it. Anyways due to a different warm restart problem I had my local MB shop replace it. Sure enough, it didnt fix my problem and the new one buzzed just like the old one.

[JimSmith]

I just went through this on a 1986 190E 2.3-16. On this car the fuel pump buzzing noise was accompanied by the pump running longer and longer between intervals of being shut off. The fuel pump has an integral check valve assembly, and it is my belief the fuel pump check valve is the buzzing problem. When the check valve fails the pressure in the discharge line is not maintained and the pump runs nearly continually. The motor in the pump is not a continuous duty rated motor and it degrades the longer it runs in this condition. Ours just failed and replacing it resulted in a three second or less zipping noise, followed by a lengthy shut off period. Even when running the check valve noise was very slight. I will dissect the old unit and check the valve guts out this weekend. Jim

[LEADFOOT]

I have a noise that sounds almost like an insect in your ear before you slap it. That is to say, the noise is higher-pitched than a buzz. It's a whining. I located the source of the noise from underneath the rear seats and I believe that it is the fuel pump.

Is this the type of noise you are describing? I have the same problem and it's very noticeable inside the car and from outside the car while running.

The noise is the only sypmtom, no stalling that is.

Is this a warning that I need to replace the fuel pump in the near future? could it be anything else?

Thanks for any feedback you may have...

[Jim Anderson]

Try running the air conditioner. Mine has a fuel cooler and the buzzing stopped when I did that, but that just indicated it didn't like running warm.
I think it's not the buzzing but the change in buzzing. Mine started getting louder (could hear it on the freeway) over a couple of weeks then started having fuel starvation problems (stumbling under full power). I changed them (I have two) before I got stuck. The pump had a rattle when I took it out.

[cc260E]

[ The fuel pump has an integral check valve assembly, and it is my belief the fuel pump check valve is the buzzing problem. When the check valve fails the pressure in the discharge line is not maintained and the pump runs nearly continually. Ours just failed and replacing it resulted in a three second or less zipping noise, followed by a lengthy shut off period. Even when running the check valve noise was very slight. I will dissect the old unit and check the valve guts out this weekend. Jim[/QUOTE]

Hi Jimsmith did you have time to dissec the fuel pump and the check valve? what is your conclusion? Any pictures?

I am interested to know the result. My car ( 260E 1988 EURO) has erratic stalling/loss of power since years.
Investing on faulty unit is always very helpful to all members to understand troubles

[LEADFOOT]

My humming/buzzing/whining noise is constant and has not resulted in a loss of power.

I'll change out the fuel pump and report back.

Was reading in the 'E Class Bible' that it could also be a clogged screen in the fuel distributer or in the fuel tank. Has anyone had either of these problems and had this noisy fuel pump?