Councillor drinks milky coffee, making loud noise (7)
I believe the answer is:
clatter
'loud noise' is the definition.
'councillor drinks milky coffee' is the wordplay.
'councillor' becomes 'cr' (I've seen this in other clues).
'drinks' is an insertion indicator.
'milky coffee' becomes 'latte' (I've seen this before).
'cr' placed around 'latte' is 'CLATTER'.
'making' is the link.
(Other definitions for clatter that I've seen before include "(Make) a rattling noise" , "noisy commotion" , "Loud rattling noise" , "Jangle and crash" , "Make a rattling sound" .)