jimbobs

as the title says, im getting a terrible noise in a morning when cold, if my foot is off the clutch its not there but if I slightly put my foot on the clutch its starts pulsing/vibrating/buzzing in the peddle n sounds like its coming from the clocks??? very strange and very loud, if I push the peddle a little harder and take up the bit of free play it goes away! it lasts 3 or 4 mins in a morning then goes! n doesn't to it the rest of the day! any ideas? cheers