hopefully it's the thermostat that's gone these cost anyting up to £20 & fairly easy to fit,the other thing's to check are the engine oil to see if any water is mixed in with it (should have a creamy residue on oil filler cap)if this mayo is visible it may be the headgasket gone,have a sniff test done at your local garage this will tell you for sure if the head gasket has gone
GHOST
February 2011