tapping noise

hi this is my first post. i have a tapping noise which seems to be coming from the fuel pump on my 1994 300tdi 255000 on the clock.The noise is like a noisy tappet it seems to come and go.any suggestions?.

Hi,

Does it vary depending on how much fuel in the tank ? When did you last change the fuel filter, and have you changed it regulary !!

I'm thinking the pump may just be worn, especially if it's the original with 255k miles, that's one hell of a lot of run time for a fuel pump !!!

what sort of revs do you achieve if you just deck the throttle in neutral?
if it's not hitting the limiter then its a sign of a tired fuel pump or restricted flow, Change your filter anyway - the're cheap enough!

Thanks to Disco Steve and Battenburg for the replies. I appolgise as I may have given you the wrong information. The tapping noise is from the fuel injector pump and not the tank fuel pump.
Any ideas?
Thanks
Alan

alan morgan said:

Thanks to Disco Steve and Battenburg for the replies. I appolgise as I may have given you the wrong information. The tapping noise is from the fuel injector pump and not the tank fuel pump.
Any ideas?
Thanks
Alan

Click to expand...

If it's a Disco TDi 300 then it doesn't have a pump in the fuel tank, just a sender unit for the fuel gauge and off course the pipework to get the fuel out !!

If the ticking is in the engine bay, it could well be the fuel lift pump.

Under what circumastances you you get this noise? Is it engine speed related? If you can locate the lift pump (behind and below the fuel injection pump), get hold of a long screwdriver or similar and put the pointy end on the lift pump and your ear on the other - you'll soon know if it's that that's the problem as the noise will be amplified.

Hope that helps.
Cheers & good luck
Dave

are you sure it's not your vacuum pump - that's a common source of that type of noise.