Fuel Pump Buzz?

[PeterC]

Had a most enjoyable day out at TMS on Sunday. meeting lots of old friends. Drove home without problem until I put the car away in the garage?

TVR Chimeara 4.5 - 2000 "W" reg.

Ignition ON, press immobiliser keyfob and you can hear the fuel pump priming the system and then stop - all as normal.

Turn the key and start the engine with no problems. But when you listen carefully, you can hear a new continuous buzzing sound from around the near-side rear wheel, suggesting that the fuel pump is running continuously? This noise is not normal?

I can find no evidence of fuel leaks and the tank is confirmed to be at least half-full. I have re-read all the threads on P/H's regarding fuel pump relays, but my symptoms do not match any of those?

Any suggestions as to the possible cause and cure would be most welcome.
Peter

[K4TRV]

PeterC said:

Snipity - you can hear a new continuous buzzing sound from around the near-side rear wheel, suggesting that the fuel pump is running continuously? This noise is not normal? - Snip Any suggestions as to the possible cause and cure would be most welcome. Peter

The Pump must be running continously to provide a pump pressure of 35/40 psi - What I suggest you have is, a pump that is starting to become noisy, or you have just noticed the noise. I would doubt anything was wrong - does it not run smoothly, pick up cleanly ?? If not then the pump is probably on the way out. But the pump definately runs as long as the engine is running.

Trev McM

[aaandy]

Hi,

Have a read of this. www.pistonheads.com/gassing/topic.asp?f=8&h=&t=52678

I posted a similar question a month ago after noticing the same noise. But it would appear that it is totally normal and that you haven't noticed it before, coupled with the fact that some conditions (i.e. if it is very hot) may make it a little louder than normal.

But the bottom line is that you probably do nt have anything to be concerned about. I have stopped noticing it and all still running fine 1000 miles later.

[GreenV8S]

Does get louder when the fuel is very hot which is probably what has heppened in this case. It also get noisy and rattly when the pump is on its last legs. If it still does this when everything is cold, it might need attention.

[5ltvr]

mine also gets louder and very buzzy when petrol tank nearly empty - quite a handy warning, just like tvr to think of something different and not mess about with lights on the dash

[5oo fun]

i was at tms too and my 5L is the same when low on fule after just 18000 miles

[V8 Archie]

I get the same. It's almost inaudible from the drivers seat, but since I first noticed it (from the rear of the car) I can now hear it most of the time.

I'm pretty sure it's no problem, just that your brain is expecting to hear it so it picks the sound out of all the engine noise.

[PeterC]

I definitely could hear a significant noise from the area of the pump, which following testing last night, has now disappeared.
The conclusion that I have reached, is that the problem may have been caused by me leaving a hot car parked on my sloping drive. I left the car parked for some 40 minutes after arriving home (which is unusual, I normally put car straight into the garage).
I presume that the fuel pump was having a problem achieving the correct pressure with perhaps a vapour lock somewhere along the pipe. Anyway, it seems to be OK now. Thanks for all responses received.

[.Mark]

5ltvr said:

mine also gets louder and very buzzy when petrol tank nearly empty - quite a handy warning, just like tvr to think of something different and not mess about with lights on the dash

Yep we've noticed that too, always a good indicator. Although I do have a more reliable system:-
Wife usually drive the Chimaera to work as I use my company car. Somedays however, she asks to use my car, thinks me so jumps in the TVR to use that for work, only to find it almost empty.

We also have an XR2i for emergencies and the fuel pump does the same on that, louder and louder as the fuel level goes down.

[yiw1393]

5oo fun said:

i was at tms too and my 5L is the same when low on fule after just 18000 miles

That has GOT to be a record!