My standard UK 1996 Impreza turbo with FSH and 73k has just started making a horrible knocking when starting from cold (left overnight) Seems OK when warmed up. Sounded fine last week - only thing to change is I fitted new alternator belt over weekend.

Any one know any good specialists in or around Glasgow?

 

Check the bolt on the crank pulley is secure and there is no play in it, if they come loose they sound horrific.