Turbo's are made to run hot, they are part of the exhaust. I would think it's more about cutting off the all-important oil pressure when turning off the ignition causing excessive wear on the bearings when the turbo is still trying to dissipate its kinetic energy and spinning down from 13 gazillion RPM. Best let it idle for a bit before switching off if you pull in to a rest stop from highway speed. More cooling due to the coolant (and oil) still being pumped through it is a nice bonus.Coligny wrote:Well, it was more aboot turbo cooling after engine shutdown than fanboyism...
For the others:
Issue especially on 2000' 1.8T for VAG, after shutdown the engine cooling just stop, with turbo still hot (since it was a small one to make up for displacement at lower rev it was kicking early and therefore always be on the warmer side even for supermarket runs). Sooo that meant that you had a engine bay working like a dutch oven. The timer is used to idle a bit a shutdown to allow for some cooling.
It's not a factory option because it ruins the mpg rating... And these days with idle stop it might be quite a mess to install...
Not that manufacturers generally give two shits about things that might happen when the car is out of warranty, which is of course how you get stop-start systems on turboboosted engines.