Hiya Don't know if any one can help but i have a 1.9tdi galaxy y reg that started over heating, but if you parked up with the engine still running it would cool down. The engine was hot and all coolent pipe's were hot except the one from the thermostat housing to the radiator which was cold! The radiator was cold too and no heat through the vent's when heater was on.I have removed the thermostat and now the pipe from the housing and the rad it self is getting warm but still no warm air inside the car even though temp gauge was half way and although the car was fine for the last week without the thermostat it has started over heating again so i am now thinking head gasket! but is there anything else i should look for 1st? i checked thermostat in boiling water and it is definitly faulty. thank's for reading mark