Next step is to make sure the thermostat isn't stuck closed,if your radiator has a filler cap on top and you can see the water,run the car engine and the water should be still,when it heats up you will see it flow across the top of the rad.Better still take the stat out and replace it,they don't cost much.You could take the stat out,replace the cover and run the car without it,it should hardly heat up much at all,best to replace it.
Rich
January 2008