Quick question to you all. This is my second turbo vehicle in the past 10 years. My first was a late 90's turbo Volvo. It was recommended by the Volvo SA's that you let the car idle for a bit after driving before turning the engine off. It would help cool down the turbo. I have been sticking to this rule of thought on my new Mini S, but thought I'd check to see if this is still valid. Thanks

 

i don't believe so because the mini uses an electric pump to circulate oil through the turbo after shutdown...

someone correct me if I'm wrong...

 

The R56 MCS does have an auxillary pump, however it's in the coolant system. You can hear it run quietly behind the front grill after you shut off the engine, and it'll run for a few minutes after shutdown to pump coolant through the turbo bearings.



From realoem.com: Item #1 is the "additional water pump" for a coolant circuit for the turbo.

 

thanks... I knew it did something.

 

Yea, like they said it has a coolant pump that runs after shutdown. But I still find myself letting it idle for a second after ive driven hard at all.

 

also worth noting that water coold trubo bearings run muich cooler and need much less time to cool down after a hard run.

the fact that the MINI uses a aux coolent pump means they have already concidered these problems,

CHris.

 

My non-turbo mazda does that...depending on the heat...

 

letting the car idle for 30-180 sec. is a GREAT idea prior to shutting the engine down. Especially after a hot run. This allows the cooler oil from the engine and crank case to be pumped through the turbo. Not doing this allows ULTRA hot oil to then gel inside the oil return line.

Not mandatory, but certainly a good idea for longevity of the turbo.

 

Adam is 150% correct, even if you are not autocrossing, let the oil in the turbo go through another pass in the turbo so it does not settle with hot oil. The aux water cooler will send the coolant through the turbo after the car is shut off and I do not think you should hear this very often if you are simply a daily driver and not overworking the car.

 

Could get an alarm with a turbo timer.

 

This is why the car has a aux coolant pump; to pull heat out of the center cartridge and some of the heat in the fluids in it, including the oil. If we were talking turbo-kits on the R53, I would wholeheartedly agree to let the car idle for a minute after driving hard, but on the R56, it's built-in. Park it and forget it.

 

But the pump is just keeping the oil flow thru the system and the fan isn't running. So it really isn't cooling down the oil that way.

 

The AUX pump pumps coolant, not oil, through the system after the car's shut down. And even without the fan running, the coolant being pumped through is going to be *much* cooler than the internals of the turbo, so it will still remove heat. You only need to cool the turbo down below the flashpoint of the oil so that the oil doesn't evaporate in the turbo and leave deposits behind.

Right after you shut the car off, the coolant temperature is going to be around 195-200 °F, and the flashpoint of oil is in the 300-400 °F range, depending on the type/brand of oil and how many miles it's been in the car. So even without the fan running, the "hot" engine coolant is still "cold" enough to cool the turbo down and prevent oil coking. (Is it still called "coking" with synthetic oil?)

 

Ah, thank you for clearing that up. All this time i was assuming the turbo was oil cooled!