318I A/C or auto problems

[bwick]

Hi all, I have been checking this site for some time now to resolve small problems and think it is great,My turn with a problem can anyone help,
Firstly, I have a noise that only comes in when the climate control is on, this noise is not there all the time just seams to come in and out with the engine reving etc, turn the a/c off and away it goes, or when driving and noise comes in if you go a bit faster the noise may change pitch and go away or go slower and it may go away .
I had herd that the lower fan motor in the climate control does give problems but this noise also seals to go inline with the auto change as well can anybody help !.

Bob