The is evidence of coolant leaking around the water pump. Coolant seems to be dripping down the pipes going into the pump or is dripping from the pump on to other parts of the engine.

Engine Temperature warning light showing on dashboard

The engine temperature warning light shown in the picture (or one very similar depending on the car manufacturer) has appeared on the dashboard and stays on.

Engine doesn't start up and/or cuts out when running

The engine doesn't start up very easily and will often not start at all. When it is running it can cut out completely without warning.

Engine temperature is higher than normal

The engine temperature reading on the dashboard gauge is noticeably higher than usual. It doesn't seem to be caused by sitting in traffic on a hot day, it is generally just higher all the time.

Coolant leaking onto floor under car

On inspection underneath the car there is a puddle of coolant, the liquid is clear in colour and the texture is not like oil.