I have just bought a 52 plate vectra (at an auction) and the temperature gauge does not move from cold. Is this common? if so, how do I fix it? Or, could the thermostat have been removed to over cool the engine to hide a more serious issue (head gasket perhaps) Thanks Paul.
It could be just a faulty sender unit - if the coolant level stays constant over time I doubt it would be the head gasket.
It is possible that the thermostat has stuck in the open position.
Check the sender unit first.