I've read in a couple thread that idling prior to shut down, or driving more conservatively just prior to shut down can help the turbo cool down. Why? Does it work?

What makes the Turbo kick in? Does the turbo spin during low speeds and steady highway driving?

Thanks!

 

Our Minis have a device to help cool off the turbo. The benefit of idling the engine for a minute with no input is that it helps cool off the turbo bearings prior to shutdown. This prevents the oil literally cooking on the bearings as well as a bunch of other things that I'm too tired to think of at the moment. The long and short of it is, let the car idle for 1 minute or so if you just hauled butt down your street. If you drove in very conservatively, you are probably safe just shutting it down as soon as you pull in.

 

The turbo is spinning all the time.

Letting the engine idle or driving conservatively prior to shutting down the engine was more important in the early days of turbochargers, especially with conventional motor oil. If you didn't, the super-hot bearings in the turbo would "coke" the oil when the oil stopped flowing as a result of the engine shutdown. This caused the oil in the bearings to evaporate, leaving behind hard deposits that would eventually ruin the bearings. Modern synthetic oils are much more resistant to coking.

Also, with the MINI (and many other modern turbocharged engines), the turbo is cooled both by engine coolant and the motor oil, and there's an electric pump that keeps the coolant flowing through the turbo for a little while after you shut down the engine, cooling the bearings down even with the engine shut off.

So, unless you've really been beating on the car immediately prior to shutting it down, there's nothing you need to do in the way of a "shutdown ritual" to protect the turbocharger.

 

Regarding the pump running post-shut down; sometimes I hear something running, most times I don't. When it does run, it's usually less than 30 seconds. Should this come on after every shut down, and for how long?

Thanks!

 

I'll bet it's temp related and only runs when it needs to. If you've been driving city speeds and park, chances are it doesn't need to run, the turbo only really gets hot when you're "on" it.......

If you ran a track event but take a cool down lap and drive slowly into the pits, even then it wouldn't need to run much, you've cooled it down already.

What you don't want to do is run it up a mountain, pull into a rest area at the top and shut it down - that's when letting it idle a minute would help - otherwise, don't give it a thought.........