help! noisy radiator

well there was no improvement and it woke me up again about half bloody 6 this morning.

So it looks like I might have to get it replaced.

Is it an easy enough job now that the tail piece on the radiator has been changed? It would just be a straight swap?

It just means draining the whole system again.

Which type should i get? I know the drayton ones work ok on my system as there is one elsewhere in the house.

ive just done a little experiment on it and it is making a whooshing / glugging noise once it reaches the temperature that the valve would open or close

also ive turned down the heating pump for a bit, to see if that helps.
( which it is so far)

is it possible the water pressure is too high?

is it ok to leave the pump set to number 1, all radiators still seem to be getting good and hot.