freelander diesel wheel arch fuel pump

hi all,
can anyone help,as soon as i turn the ignition on on my 03 freelander there is a buzzing sound coming from the diesel pump,sounding a bit like a whale pump on a caravan if you get me drift,
even when im driving i can stilll hear a buzzing noise,it drives ok but when you put your foot down it chuggs a bit as if wanting more fuel,
anybody had this problem affore

The pumps on these cars are a bit pants. Usually result in a complete non start, or engine management light comes on and wont rev (usually) past 3000 rpm...

If it is getting a bit noisy now, may be worth replacing it before it fails completely

or at least buying one now for the happy moment when the current one goes completely pete tong