I came across this paragraph in my car manual which states the following:

"If the engine has been driven hard for a long period, the engine could overheat when it is switched off. Risk of engine damage. For this reason, you should idle the engine for approx. 2 minutes before you switch it off."

Makes sense although it's a little ambiguous, what is typically considered "driven hard"?

Typically if I'm driving in very hot weather after a long motorway trip I usually wait until the radiator fan stops spinning after which I turn off the engine, I assume the fan is going to keep spinning until the coolant is below a certain threshold, is this unnecessary?

For reference:

Car: 2004 Seat ibiza 6L

Mileage: 110000 km (63000 miles)

1 Answer 1


A motor vehicle operating at high speed with a functioning cooling system will have airflow through the radiator of sufficient volume to allow the thermostat to close to maintain normal operating temperature. This is common on high speed roadways, in the USA known as interstate highways.

Leaving these high speed thoroughfares and traversing surface streets for any reasonable period of time (five to ten minutes or more) should result in the thermostat opening to continue to cool the engine.

I feel it would be a rare circumstance in which an automobile would overheat when changing from high speed, high load, normal cooling to an off state, but your manual clearly cautions about this. Your description indicates you have an electrically powered thermostatically controlled radiator fan, which would take into consideration the appropriate temperatures within your engine and would also allow for the hotter coolant inside the engine to travel through the opened thermostat to the radiator for temperature reduction via the fan.

I believe your practice is in agreement with the manual if you allow that you are more observant than the operator for which the manual is written. Imagine that the manual has written in invisible ink that you can use the fan as an indicator for suitable cooling prior to shutdown. You may have also provided an appropriate cooldown by your travels between the area of high speed travel and your parking location, resulting in a short duration fan operation.

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