thanks for the reply Guys. The car is currently with my mechanic now, today whilst breaking the engine down & doing the tests in preparation to change the oil cooler he found that the water pump housing had a slight leak so in the process I’ve now purchased a new water pump & housing along with a new thermostat. we will check to rule out anything else more sinister out tomorrow as quite a few forums jump straight to a head gasket problem first. Hopefully it’s just what’s suspected in its diagnosis & fingers crossed we can crack on to change the parts & resolve the issue. 🤞🏽