AaaHa,

A little more information.

for low coolant level, read overheating indication!

1500mile trip, in new car purchase, is there a medal for that.

Lets just suppose, it is a V6 3.0ltr, and why not.

and the coolant has not been changed for some time, give it a good run. 1500miles in my book is a good run.

The rubbish in the coolant system get stirred up, and causes the expansion valve to get sticky, and not open fully. Fan takes over and tries to cool engine coolant.

The Electric Fan screams like a banshee at high speed.

Yes could be that, expansion valve sticky, but hard to tell with out a bit more information.

Then again if it were a 4.2 V 8 it could be the thermostat housing which fractures internally recirculating the coolant around the water pump.

another stab in the dark.

This could be a long thread.

 

It is always helpful to include the engine type/size and the number of kilometres/miles indicated on the instrument cluster. Also mention if any work has recently been performed on the vehicle cooling system, or other parts of the engine requiring the cooling system to be opened.

From your description, it seems to be an incorrect or stuck thermostat and perhaps low coolant level.

After a cold soak, remove the cap on the expansion tank and check the coolant level. The system should also be pressure tested when cold to determine if any leaks are present.