General Fuel Pump Humming.

[Adam1984]

Hello,

Can anyone please tell me, if you have a Panda 1.2 Petrol, engine code. 169.A4000, when the car is running does the fuel pump make a constant humming noise from the rear seat area, or is there no sound at all? Thanks.

 

[Herts Hillhopper]

Most cars ‘hum’ from there. There’s an electric pump in the fuel tank (which is under the rear seat) that sends fuel to the front, and then a mechanical pump on the engine to pressurise it for the injectors.

The electric pump will hum/buzz/whine (depending on make/model of car) when the key is turned on (even if the engine isn’t running). Many also continue to make a noise for a short time after the key is turned off again. All this is normal.

 

[Adam1984]

Most cars ‘hum’ from there. There’s an electric pump in the fuel tank (which is under the rear seat) that sends fuel to the front, and then a mechanical pump on the engine to pressurise it for the injectors.

The electric pump will hum/buzz/whine (depending on make/model of car) when the key is turned on (even if the engine isn’t running). Many also continue to make a noise for a short time after the key is turned off again. All this is normal.

No I mean the humming is constant... So even when am driving. It's always humming constantly. Primes when you turn the key to MAR, but then when engine is running and taking the car for a drive. It's always humming..

 

[Herts Hillhopper]

No I mean the humming is constant... So even when am driving. It's always humming constantly. Primes when you turn the key to MAR, but then when engine is running and taking the car for a drive. It's always humming..

Yes, it primes but then stops if the engine isn’t started. But all the time the engine is running, that pump operates otherwise no fuel will reach the engine. My 62 year old ears can’t hear it while driving though.

 

[Adam1984]

Yes, it primes but then stops if the engine isn’t started. But all the time the engine is running, that pump operates otherwise no fuel will reach the engine. My 62 year old ears can’t hear it while driving though.

But mine can be heard quite strongly. So suggest there is some sort of issue with it.

 

[Herts Hillhopper]

But mine can be heard quite strongly. So suggest there is some sort of issue with it.

Maybe… but (with respect) you also seem to hear and be troubled by noises that most of us don’t notice. Has it always done it, or has the noise changed? There’s a crude mesh filter (more like a sieve) around the pump but I have never heard of anyone needing to change that (again, on any make/model of car since fuel injection came along in the 1990s)

I can’t hear mine when driving…

 

[puntodad19]

The pug 306 diesel I had, the fuel pump in the tank could be heard priming the system then stop if engine was not started.

I could never hear the pump running whilst driving.

Then one day it started to be louder, and could be heard whilst engine was idleing. It was under the car port at the time.

I left it idling when I went for a pannad. When I returned a few moments later, the engine had stopped. Odd I thought.

Engine refused to start, no noise heard from tank pump, it had died. It had covered 130k miles.

When the tank is about 1/3 full, the pump motor is submerged in diesel.

Returned warmed diesel to the tank is directed inside the pump unit over the pump motor.

There is a *trap door* one way valve involved with the pump unit so fuel can fill the fuel pick point. There is a fine white plastic mesh filter on the end of the fuel pick up pipe, and a paper fuel filter unit under the bonnet.

When I first got the pug, *gold coloured glitter* was seen on the bonnet filter floor. Fuel pump drbris ?

When changing the pump unit, the same glitter was seen on the tank floor.....

Apparently, the pump gears where brass.

 

[Mike1alike]

There’s an electric pump in the fuel tank (which is under the rear seat) that sends fuel to the front, and then a mechanical pump on the engine to pressurise it for the injectors.

That's the only fuel pump, in tank one on Adam's model. That provides pressure, it has a mechanical pressure regulator in tank, in the fuel pump assembly, that let's extra fuel back in the tank and keeps constant steady 3.5 bar fuel pressure. The second fuel pump next to engine is on different engine type, that is usually a high pressure pump. That brings not much good and very much bad when it goes faulty.

But mine can be heard quite strongly. So suggest there is some sort of issue with it.

Yes, if you can hear it with engine running, it's not ok. Something is faulty on it. It does humm when engine is running, but very muffled. Engine noise covers pump's noise, you should not hear the pump noise. My son tells me it cannot be heard even sitting on the back seat.