Quote:
Originally Posted by ITSv40
The OP's car is behaving perfectly normally. Having switched off the engine and the car is stationary, the underbonnet temperature will rise and possibly activate the cooling fan to reduce the temperature. The length of time the fan runs is dependent on a, the engine temperature and b, the ambient temperature. That is why there is a yellow warning sticker under the bonnet stating: Self starting fan, keep hands clear.
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The sticker is there because the fan remains live even with the ignition off, so potentially can start. The cooling fan isn't there to cool the engine down. Water does that. The fan is there to supplement air flow over the radiator when stationary, to radiate away the heat from the water contained within.
Furthermore, there's a misnoma occurring here. The "thermostat" isn't even what switches the fan on and off. That is the job of a rheostat which is housed inside the radiator. It measure water temperature, not air inside the engine bay, so this "engine bay will get hotter" is false. Whoever heard of an engine getting hot when it's switched off anyway?
There is also the OP's original post where he seems to imply the fan starts only after the engine has been stopped, which is certainly a fault. Which is why I requested more detail.
None, absolutely none, of any of my cars have ever decided they're too hot when switched off. Ever.