I had this worry with my golf when i first got it and was going to change everything but left it idling and my rad fan only comes on at three quarters

mfa sits around 85-97 and most has been 110 but I'm running her in! <grin> def try expansion cap and check oil cap for mayonaise looking gunk could be head gasket does it steam a lot on a morning? other than that my dad swears by mustard powder and a raw egg!!!!!!