Have the same problem!!! Right now!! Gary wood of alive tuning found the problem when doing my car, there is copper filaments in coolant cap which can be a sign of leaky head gasket. Got new cap! Uv dye on way, then ultimately it is the head gasket!!
Scotland is never really sunny! I go to Alness and Tain it's never been sunny, my dad was from there and is buried there, whether I go by car or plane I am always astounded by its raw natural beauty... And harsh environment!!!!