Advise needed on tyre pressure sensor valves
 

I was checking round my x5 today that I have just bought and noticed that 1 of the tyre valves had corroded away so bad it looked like it was part of the rim. I removed the tyre and managed to remove the valve. I tried putting a normal valve in to get me home until I can get a proper 1 but found it to be very loose in the rim and leaked when inflated. Does any 1 no if the sensor valves are bigger than standard rubber ones or has it corroded away some of my rim? Any help would be great
Rich