Turbo cool down

[mr. shr]

Quick question:
Are we supposed to let our tubro charged engines cool down before we switch off?

I've heard people do this on skoobys and impretzas etc. to prolong the life of the turbo, but is this something you do with every car fitted with a turbo?

 

[moonloops]

Quick question:
Are we supposed to let our tubro charged engines cool down before we switch off?

I've heard people do this on skoobys and impretzas etc. to prolong the life of the turbo, but is this something you do with every car fitted with a turbo?

No you don't and impreza's evo's don't need to do this either.

What you are supposed to do is not use boost for the last 3 or 4 mins of your journey. This gets water/oil circulated around the turbo and some of the heat wicked away before you shut down.

 

[flango]

No you don't and impreza's evo's don't need to do this either..

They most certainly do unless you want to kill the turbo and how do you not use the boost? Any high performance turbo charged engine should be allowed to idle before switching off, how long depends on how hard you drove it, drive it hard and then kill the engine immediately and it's goodbye turbo bearings.

Good practice dictates just let them idle a while before shutting down it definitely prolongs turbo life

 

[moonloops]

They most certainly do unless you want to kill the turbo and how do you not use the boost? Any high performance turbo charged engine should be allowed to idle before switching off, how long depends on how hard you drove it, drive it hard and then kill the engine immediately and it's goodbye turbo bearings.

Good practice dictates just let them idle a while before shutting down it definitely prolongs turbo life

Thanks - but re-read my post about doing the cooldown whilst still driving

 

[mr. shr]

So this is only something you need to do with high performance turbo engines?
We're ok with our CDi engines?

 

[EDZ649]

It is good practice to let the engine idle before shutdown with any turbo.

 

[mr. shr]

So do we all do this with our cars?

 

[moonloops]

So do we all do this with our cars?

Nope, I just drive off boost last mile before destination.

I've owned approx 10 turbo car's including jap spec impreza's and never had any of them sat idling after parking up.

 

[wemorgan]

I'm the same as moonloops. Most people live in residential areas, so by nature the last few miles can be slow off-boost driving.

 

[corned]

As above - it depends on your location.

If you live at the bottom of a motorway exit sliproad then yes, you should let it idle for a few minutes.

As I live in a residential area with fairly narrow twisty roads, I have no option but to wend my way slowly for the last 3 or 4 minutes, therefore it has ample time to soak away the motorway heat build-up.

I wonder how many people think to give their car a couple of minutes to catch its breath when stopping at a motorway services though - particularly if you have been giving it the beans on a long trip?

***?

 

[Frankie]

Run it off boost the last few miles home.But as said above,if you come to you destination straight off a motorway etc,let it idle for a bit.

 

[timskemp]

As above - it depends on your location.

If you live at the bottom of a motorway exit sliproad then yes, you should let it idle for a few minutes.

As I live in a residential area with fairly narrow twisty roads, I have no option but to wend my way slowly for the last 3 or 4 minutes, therefore it has ample time to soak away the motorway heat build-up.

I wonder how many people think to give their car a couple of minutes to catch its breath when stopping at a motorway services though - particularly if you have been giving it the beans on a long trip?

***?

Giving it beans? If you've got a 150mph car you're using less than 1/4 of the power driving it at 100mph. If you're cruising at much more than that then you're going to be banned well before you cook the turbo.

My street is narrow and windy, just makes it more of a drift challenge...

 

[alexanderfoti]

My friend has a scooby with a turbo timer, people keep coming up to him saying that his car is still running.

But yes, he leaves it running whenever he gets to his destination for a bit.

 

[flango]

Thanks - but re-read my post about doing the cooldown whilst still driving

You cant do the cool down whilst driving because unless you are very experienced you cant tell if the turbo is spooling, on boost, or not, I defy anyone to drive a high performance turbo car without using some boost, even with a boost gauge it's impossible.

The oil needs to circulate on tickover so most of it drains back to the sump not at rev's when driving as if there is excessive heat the oil burns and sticks to the bearings and ruins them

Thats why all the serious high performance jap cars, rally cars and race cars use turbo timers.

 

[mr. shr]

Thanks for the input guys.
I rarely boot my 211 (mainly in fear of it breaking!!), but in future will remember to be extra carful for the last bit of every journey.
Most of the driving is down around town anyway, so little need to give it the beans.

 

[prc]

No one mentioned that a diesel will run lower exhaust temperatures so cooking a bearing with immediate shut-off is not as easy on a diesel. The CDi also comes with a vnt turbo so a bit harder to be off boost, even at lower rpm.
On my 7th turbo diesel and only let it idle for a bit after trashing it a bit (<0.5% of the time).

 

[wemorgan]

The cooling down issue from a spirited drive will vary from car to car. I've read the below about the VW 2.0 TFSI engine

"To prevent carbon build-up on the turbine shaft in the turbocharger, an auxiliary coolant pump provides additional coolant circulation for a certain time after the engine is shut off hot. The pump forces the lower temperature coolant against the normal direction of flow. The coolant flows from the radiator through the turbocharger to the engine block and back to the cooler."

If this technology is available on a VW I imagine something similar will be on more premium vehicles too.

 

[kwakdonut]

The cooling down issue from a spirited drive will vary from car to car. I've read the below about the VW 2.0 TFSI engine



If this technology is available on a VW I imagine something similar will be on my premium vehicles too.

Nothing that fancy on the 211. I changed the turbo on mine last year - bolts to manifold with pipes to exhaust and intercooler. One electrical connection and the oil feed pipes - that's all!!

I have always let all my turbo-equipped cars cool for a minute or two although, like most, any motorway/spirited driving is followed by a gentle <30mph through town before I get home.

 

[grober]

The original Porsche 944 water cooled turbo model had one of the first post engine shutdown coolant circulation timer setup as standard from the factory iiirc.

 

[bigjim]

No you don't and impreza's evo's don't need to do this either.

What you are supposed to do is not use boost for the last 3 or 4 mins of your journey. This gets water/oil circulated around the turbo and some of the heat wicked away before you shut down.

You are right Moonloops - its about driving off boost to allow the turbo to slow down whilst still being cooled.#

Admittedly, sitting at idle does the same thing but there's no need if you've been driving off of boost for the last few miles.