Ok guys just pulled up at home and heard a strange noise coming from engine popped the bonnet and for some reason felt the rad and the top was all hot and bottom was stone cold inc bottom hose and I'd just done 30 miles and don't know where to start with it the noise was sort of like a rattle like a pully was lose ? Done a search on here and all it comes up with is head gasket now there are no tell tale signs of this so I'm stumped any idea guys and I will start to have a look in the morn

 

Sticking/stuck thermostat ?

 

Does the engine overheat ?

On a warmed up car, put your heater on full, is the air coming out of the vents hot or cold ?

What sort of rattle ?

Any coolant leaks anywhere? Around the timing belt area ?

 

possible water pump failure if its not pumping it round the engine.

 

Been any work done on the cooling system recently?

Reason I ask is it sounds airlocked.