Turbocharged diesel engine
In the cooling system of a turbocharged diesel engine, an additional coolant pump (arrow) is installed next to the gearbox housing.
The pump is switched on after the engine has stopped at a coolant temperature above +107°C and maintains the circulation of the liquid. This eliminates overheating in the turbocharger area first and foremost.
When starting the engine (while the starter is working) this pump is also switched on to prevent its failure due to prolonged inactivity (for example, in winter).
[The text is copied from this portal: vwmanual.ru]
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