Should I allow my turbo to cool down?

[giblets46]

Hey all,
I was wondering, having read about petrol turbos, and how they advise you to idle and cool the turbo before switching off the engine, is this advisable on a diesel turbo too?

 

[Rev-head]

Yes exactly the same

 

[arthurfuxake]

I idle mine for a minute each time. I also make sure that I'm not full on the turbo too close to my destination so that it is cooling down as I drive.

 

[Mcgough]

You will find its best to drive gently on way back just for the oil to settle and not to just cool down the turbo as the engine will hold its heat(and turbo) for ages after you stop so should cool gently in any case!

 

[fjtwelve]

Yes

 

[timps]

The main problem used to be oil starvation to the turbo bearings & not really a temperature thing .

The turbo would still be spinning at high speed and if you switched the engine off this would cut the oil pump and starve the bearings of fresh oil causing premature wear /failure to the bearing whilst it was still spining.

So you would let the turbo spin down before turning the engine off.

This used to be a big problem on MF tractors but most modern engine manufactures are now aware of the problem and take steps to prevent this oil starvation happening.

 

[Teejay]

The main reason for having a turbo timer on a petrol car is because of the ludicrous temperatures involved, so you need a couple of minutes of gentle driving/idle to allow it to cool enough with oil circulating before switching off. A TDi runs at a much coller temperature and Audi's owners manual advises that you do not need to worry about this unless you have been thrashing the hell out of it, and even then only needs 30-60 seconds of gentle driving to sort it out.