Possiabe head gasket

best thing is to get a sniff test done,this will confirm if you have a blown head gasket,if this is ok then do a cooling system pressure test and check for leaks and also check fan is working ok and coolant sensor is ok,check thermostat is operating and that water pump is circulating coolant around system

hi there some times you get the build up of scum in the oil cap due to short journeys as its condensation but with you saying that the oil and water levels are ok then i would say it the fan switch that is the problem here or even a air lock in the system have these checked out all should be ok afterwards

Corsas are notorious for emulsified oil in oil cap , this is normal . As " thomkas_cars " says this is made worse in cold weather and short journeys .If not losing water , overheating in traffic could be rad . fan not kicking in due to faulty switch .

thank you very much all that have commented could possibly be as you said the fan as we do only do short journeys we appreciate your feedback and are going to get it checked soon. thank you again all