Just nipped home for lunch in my Audi Coupe. Slowed down to turn into my drive, and... what's that whining noise? The previously silent fuel pump now sounds like someone has left a cordless power drill running in the boot.
Any suggestions? I suspect this may be expensive. I left the car at home and came back in the Land Rover, as it is only 3 miles to work, so the AA wouldn't tow me home if the pump died on the way.
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Richard,
The obvious reason is it is going u/s but the other reason is a lack of fuel or poor pickup.
I use an old BX GTi pump and filter as my fuel transfer pump when required. I'm well used to knowing it has finished when it makes a grinding noise picking up air.
David
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My thought exactly David - Lack of fuel=noisy pump
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Some VAG (amongst others) models use two fuel pumps. The first is a small lift pump in the tank which keeps the fuel flowing to the main pressure pump. When this fails the main pump gets noisy. Inexpensive (euro car parts) and not difficult to replace. Another reason for noisy pump is a blocked fuel filter.
HTH
Andrew.
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Put cotton wool in your ears cross the fingers and carry on as normal. It sounds like an open return from the fuel system or the small pump in the tank is on the way out.
eleanor
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"Carry on as normal" - definitely not.
The Tune-Up lads are on the ball as I would expect. It sounds as if the hp injection pump situated somewhere underneath the car close to the driver's side is being starved of fuel and this is why you hear the buzzing noise as it runs dry. This is due to the lift pump in the fuel tank in the boot (below spare wheel) being on its last legs. A new hp fuel pump runs into 3 figures. A new lift pump costs £30 and can be fitted in 15 minutes.
Go to German and Swedish or other Euro-Part and get the necessary "In-Tank Fuel Pump" - fit it and you're done. Fit it soon otherwise if you keep running the hp pump dry it will go pop too and then big bucks.
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Richard,
Our A90 20V (1990, 5 cylinder) had a VERY grumbly fuel pump - sounded like mount Etna, but never 'went wrong' in any way. Just turning on the ignition was enough to create a volcanic disturbance! Our A100 CD (5 cylinder) also made the noise occasionally. My old S6 did not make any noises in that department, however.
Our current A80 16V (1993, 4 cylinder) does not make any similar noise, nor does my current A4.
Which engine do you have in your Coupe?
Martin.
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Thanks everyone for your input. My car has the 20v engine. I took it out this evening, and tried a couple of full throttle runs. No sign of fuel starvation, which I would expect if the lift pump had died. Andrew - am I right in assuming this? The pump is now no noisier than my old Golf GTi or my sister's Audi 80 Sport. Could it be that the mountings have broken, so it is now resting against a body panel? I'll take a look at the weekend.
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Richard,
I think you are right - if the pump was in serious difficulty you would experience fuel starvation. I assume from what you say that the noise has recently become worse - good idea to check the mountings.
BTW, the 20V engine is fabulous isn't it! Do you find the gear ratios curious though? (Big gap between 2nd and 3rd - you have to red-line it in 2nd to keep it over 4000 rpm (i.e. in the poer band) in 3rd?).
Martin.
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These fuel pumps do get noisy. Mine did in my old Jetta then failed. The lift pump was fine. I think the fuel pumps are £75 plus VAT for a Bosch one from G&S. It is a good idea to change the lift pump when you change the main pump. Even if you dont want to change it, it is a good idea to remove the pump so you can change the filter as these can become partially blocked and are never usually changed. Additionaly, check when the main fuel filter was last changed. I change mine every 20k miles.
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Just to confuse matters further - I left the car at home yesterday, but brought it in to work this morning, and the fuel pump is now silent.... I'll take a look at the lift pump this weekend - could just be a bad connection. It might even be the same terminal block as the heated rear window, which has also become intermittent.
Martin - the gearing on the 20V is indeed very odd. I find first gear much too tall, which is a pain in city traffic, and the 2nd/3rd gaps is a pain as well. Unless you drive with one eye on the rev counter, you end up being outdragged by VW Polos. But I can live with this for the pleasure of one of the finest mass-produced petrol engines ever made.
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