i am getting a sort of metallic grinding sound from the front wheel it is on and off and as i go faster the sound is more often but when i press the brake the noise stops even though the car is still moving.is this the wheel bearing or a warped disc please help

Sounds like a wheel bearing, as warped discs will cause vibration thru the steering wheel

Probably either a wheel bearing, or a stone under the dust shield (if applicable).

Probably either a wheel bearing, or a stone under the dust shield (if applicable).

where abouts is the dust shield you mention and if it is the wheel bearing is a costly job to fix or can a half competent person like myself have a go. thanks

In my (admittedly limited) experience, wheel bearings often buzz more at particular speeds or when turning.

EDIT: I can't remember if it's usually turning slightly towards from them (so the weight is lifted off them) or slightly away from them (so they're more heavily loaded) that makes them buzz more.

the front wheel is just making a grinding noise but when the brake is applied it stops it also doesnt always do it when moving but it will make noise with in 5 minutes of setting off and then carry on.

Jack the front of the car up and try to rock the wheel top to bottom (and left to right but you'll probably find the steering moves). If it feels wobbly, it's a worn out wheel bearing.

Careful pulling the wheel around if you're using the normal jack - don't want to pull the car off the jack, particularly if your hand is under the tyre.

where abouts is the dust shield you mention and if it is the wheel bearing is a costly job to fix or can a half competent person like myself have a go. thanks

If there is one, the dust shield is behind the disc as you look at it, and the edge will probably be visible through the wheel spokes. If there's a trapped stone, it can probably be released by flexing the shield away from the disc, but you'll need the wheel off for access, and I'd advise using an axle stand to support the corner (no need to put the car's full weight on it, it's a safety measure).As to the wheel bearing, have a look at the manual.