Below taken from last two posts at bottom of page,Motornet.ie

I think some turbo engines (The 1.8T on the Audi S3 is one that comes to mind) have a pump that kicks in, if required, to keep bearings lubed, even if car is turned off, negating the need to "limp home"Just to back up that point..taken from an audi site...

"the electric water pump cirulates the coolant after engine shuts down for a pre set time. this helps take the heat away from the turbo, and stops the oil, which is now NOT cirulating, from burning up in the turbo, bearings etc, under the extreme heat the turbo creates."

Apparently the use of synthetic oil makes this step not as critical as it used to be.

havn't heard about that but would be a logical thing to be fitted to any turbo car.

Tend to be cautious and always do it anyway and let the car idle for a while before shutting it down - once you get into the habit its comes naturally and can only help engine life.

marc

thinking about it further,I thought the problems was caused by the heat effecting the oil and in severe cases almost boiling it dry so wonder if the pump on its own would help much as you would still need to keep the oil circulating to make a useful drop in temperature.

I know that some of the higher tuned jap turbos have a preset timer to kepp the engine idling before shutting down.

to quote from "fundementals of motor vehicle technology"

"special care of the turbocharger is needed to ensure that the bearings are not starved of oil when the engine is either started or stopped.The engine should not be accelerated either immediately after it has been started or just prior to switching off.Also bear in mind that it takes a long time for the turbine to come to rest). :read:

according to the book the turbine spins at up to 100,000 rpm and the blades can reach 1,000 degrees C - thats bl**dy hot!

right thats the boring bit over you can all wake up and read a more interesting post. :sleeping:

Running the engine means the cooling mechanisms are also working. Hence the advice in the owners' manual to run the engine for a couple of minutes before switching off, particularly if you've been driving hard. Turbo timers basically do the same thing.