The manual says "leave the engine to idle
for one minute before turning off".

I do this after a hard run but is it
necessary after every journey.

What do you think?

JR

 

JR,

From what I've been told you need to let the turbo cool down after a hard run (high speed or a good back road).

To do this you either let the engine idle for a minute before switching off or drive at a slower pace for a couple of miles. Driving in a 30 zone in a high gear will let the car cool down.

DaveW

 

In reality you can usually build this into whatever you are doing such as the I dont come racing into my street and by the time I get home then the whole lot will have cooled down enough. If you trundle around gently you will usually get rid of the heat far faster than sitting still with the engine running because of the airflow under the bonnet. By the time you have done things like removed the radio put the steering wheel lock on etc etc you have usually done your time so to speak.

The only time to be really careful is when you pull of the motorway as the time here is not usually enough to let the engine cool down.

And then theres trackdays!!!!!!!

Darren

 

The 'cooling'down period usually applies after a hard run i.e.when you've been pushing it a bit.

The actual reason for the procedure is to allow sufficient oil to pass through the turbo bearing housing - the core - so as to remove as much excess heat from the core/bearings/tubine housing etc. before you switch off the engine. If you have given the engine a good thrashing - got the turbo red-hot - when you shut down the oil flow stops and the oil siting in the bearing housing absorbs all the heat and cooks.

Even the best oil will not tolerate this and coking of the housing will occur as the oil gets to boiling point. The only time I don't wait the one minute is when I have been pootling in traffic or looking for a parking space in the local superstore.

One minute of patience could save you from a dead turbo.

 

Why not just buy a turbo timer. Sure they may not be absolutely necessary and it does get anoying when people tell you that you forgot to switch the car off, but it gives you peace of mind.