E220 Cabriolet - fuel pump 'moans'

[Wally]

New issue - may be a problem, may be not.

The tank fuel pump has started to 'moan'. A very quiet moan/groan from within the car, but very apparent outside. I'm about to investigate, but thought I'd ask questions first.
How noisy are the W124 fuel pumps? How long does one last after its starts complaining? How easy are they to repair/replace?

The car although 21 years old only has 162,000 kms.

All suggstions welcome. I'll update as soon as I have a closer look, this week.

[Ivanerrol]

Relatively easy DIY if you are handy with the spanners.

Plenty of YouTube instructions on how to do this. Goggle is your friend here.

Moaning "generally" means near the end of it's useful life and may fail at any time.
Age is more the issue than the amount of K's - internal plastic bits dry out, get brittle - etc etc.

Original pumps are quite expensive - $300+ mark.
There are alternates but OEM is the way to go for reliability.

Change the fuel filter when you are changing out the pump.

[Wally]

Thank you Ivanerol - a reliable source.
Ive found the YouTube videos, and inspected both pumps. Regrettably neither is moaning now, no not sure which one is failing. I'll keep an eye/ear on them - you are right, replacement looks straightforward and I will include new filters.
And yes I agree, sometimes OEM is better.

Cheers

[ChristoC]

In my W124 the fuel pump had a definite audible murmur or whine until I changed the filter - turned out the filter was full of fine sludge; looked like mud - the noise definitely ceased after the filter change, so I put the noise down to the pump straining to push through the tight filter.
So it's worth trying just a filter change before worrying about the pump.


1986 230E W124.023 M102.982 Thistle Green Saloon "Janis"
Sent from my iPhone using Tapatalk

[Ivanerrol]

Interesting.......2 pump setup.
I would have thought the pumps for the M111's would have changed to the variety that are in the W202's - single Pierpont pump.

I have a theory that the cold weather affects the performance of the older pumps - particularly damp foggy cold weather.

Battery must be in tip top condition for those older electronics. I see in your other post that a faulty battery was giving you some concern.
I have a battery which is right on the 12.35v mark. It'll start the car and run it O.K. If you turn the AC on and the Auxiliary fans start up the engine will stall at the traffic lights battery voltage drags the ECU operating efficiency down.

[Ivanerrol]

In my W124 the fuel pump had a definite audible murmur or whine until I changed the filter - turned out the filter was full of fine sludge; looked like mud - the noise definitely ceased after the filter change, so I put the noise down to the pump straining to push through the tight filter.
So it's worth trying just a filter change before worrying about the pump.


1986 230E W124.023 M102.982 Thistle Green Saloon "Janis"
Sent from my iPhone using Tapatalk

The fuel pump in my latest acquisition $800.00 C180 W202 "pulses" when cold. The engine revs up and down in concert with the pump action.
I'll be very interested to see if it's the fuel filter causing the issue.
This car has been serviced at stealerships all it's life - 200,000km's
I'm waiting for the fuel to get down to change the filter.

[John Green]

Hello Wally, looks like our cars are twins....

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