Howling noise from fuel pump after tank replaced

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Joined
Sep 9, 2023
Messages
52
Location
London
My fuel pump now makes a loud howling/whistling noise all the time.
I'm trying to figure out why and wonder if anyone else had encountered this.

Background:
I recently inherited a Puma Millenium, which had been heavily restored (lots of replacement metal all over the place I believe, though I don't have the details yet).
It passed MOT with no warnings.
But the fuel tank leaked the first time I filled it so I had it replaced with a new OEM one, by the mechanic who'd done all the prior work. (I have no tools or jacks etc, so can't do much myself at present).
It runs fine now, but since he replaced the tank, the pump howls continuously, and it sounds awful.
I've scoured articles but not found any convincing explanations.
Some specific points:
The fuel tank is OEM. The mechanic says it's much lighter (thinner) than the original. It also has only a metal swirl pot and not a plastic insert like the original. The mechanic says it's probably because the tank is lighter and so resonates differently, but I'm sceptical of that, especially since a full tank would have similar total mass anyway.
It does not howl with the ignition in second position, only when the ngine is running.
The frequency is pretty constant, but does vary sometimes (although not entirely consistently).
It sometimes changes when the accelerator is pushed further while driving (engine under strain) but not much and not always.
Weirdly, using the electric windows affects it. The first time I noticed this I was parked and about to leave the car, so I closed the windows before switching off the engine. The noise stopped entirely when I pressed the two window close buttons. And resumed when I let go. It did this a few times and it went silent each time. But the engine continued to idle happily so I assume the pump was still running OK (or is there some inbuilt buffering?)
I also adjusted the heating fan, and this seemed to affect it too.
I've tried repeating these two things since, but it's not consistent. I do note a frequency change sometimes, and the impact seems to stop happening if I repeatedly press the buttons more than a couple of times. I also note the engine sometimes increases or decreases revs when I do this, but only sometimes and in either direction (faster or slower).
This makes me wonder if the problem is electrical, perhaps the pump straining to perform and impacted by the drain of other motors.
I can feel the vibration if I touch the tank, but not if I touch the fuel filter.

I am tempted to have the pump and filter replaced and hope for the best, but since I can't do this myself I'm reluctant to just go ahead without a better justification.

Has anybody had a similar problem or got any thoughts?
 
Hi there.
This sounds like a failing fuel pump to me.....bearing in mind it will likely be the original which is at least 21 years old.As these things age the pump will more than likely be drawing more current than normal from the battery, hence the issue when you operate your windows.
"Bullet",my silver Puma exibited the very noise you describe and ran ok,however as time went on there developed a flat spot on accelerating,showing the pump was struggling to supply enough fuel..Idling and gentle driving was fine.
A new fuel pump transformed the car.
 
The early tanks, up to about November 2000 had metal baffles and a curved fuel pipe connector. After this the tank had plastic baffles and a straight fuel pipe connector. The pump and sender sits at a different angle inside the different tanks. If you have fitted the incorrect tank the different angle may account for your fuel pump noise.
Hope this helps?
 
The early tanks, up to about November 2000 had metal baffles and a curved fuel pipe connector. After this the tank had plastic baffles and a straight fuel pipe connector. The pump and sender sits at a different angle inside the different tanks. If you have fitted the incorrect tank the different angle may account for your fuel pump noise.
Hope this helps?
Thanks. Unfortunately, I have not seen anything first-hand, so I don't know how he fitted it although he is adamant that the pump doesn't fit in a way that it touches anything. The tank he removed had a plastic insert, although the car was made in 99, so perhaps the tank was already changed at some point in the past.
It feels like the only option is to open it all up again to take a look, which I'll have to pay somebody to do as I don't have the means, and in that case I suppose it probably makes sense to replace the pump (and probably the fuel filter too) as a proactive measure.
 
Be wary of how the fuel filter joins the tank. It connects via a short plastic pipe that becomes brittle over time. I replaced mine with proper flexible fuel pipe and clips, with proper mount for the filter.
 

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