What would cause high coolant temperature when I restart the car after...

[Thomas P]

...only a few minutes? My '98 Audi A4 maintains coolant temperature well--the thermostat was replaced a few months ago. Oil temperature is also good. However, if I restart within a few minutes on a warm day, the coolant temperature nearly pegs high. It comes down to normal after a few minutes. Could this be a bad sensor that does not turn on the electric fan after the engine is turned off?

[Nomad]

Have someone watch the fan when you start the engine and tell you when the fan turns on. Check and make sure you have the right Thermostat in it. You can check that buy putting it in hot water and watch it open.
Regards,

[Nomad]

Have someone watch the fan when you start the engine and tell you when the fan turns on. Check and make sure you have the right Thermostat in it. You can check that buy putting it in hot water and watch it open.
Regards,

[Ed F]

Heat soak-this is normal.
What happens is the mass of hot metal is not being cooled while the coolant is not being circulated and transfers the heat into the coolant which is not being circulated through the radiator.