[Annona]

Owner's manual recommends to let the engine idle for a few minutes before shutting it down. So, do you do this EVERY time?

 

[ibehardnock2001]

You are only required a 5 minute cool down if you just finished a spirited run. Otherwise, feel free to shut her down as soon as you park. The Giulia is equipped with an electronic turbo cooler which you can sometimes hear running when you turn off your engine.

 

[Annona]

Thanks for the clarification.

 

[tadslc]

No on my Q and no on the 1.8 & 2.0 Turbo Audi's I've been driving the last 10+ years

 

[Chipshot]

Only if I'm having an NPR driveway moment.

 

[Simey]

Read that I should do it but never remember.

 

[lowlight]

I used to do it religiously with my 2003 Evo that I bought new... But that was when the automotive world was just getting back into mainstream turbos again.

As mentioned above, it's pretty common for turbo cars to circulate coolant/run fan operation electronically for a period of time even after engine is shut off. Good peace of mind.

The only case where I'd think twice is after a track day run...then I might let the engine run for a while or slowly drive a cool down route.

 

[[email protected]]

As mentioned above, it's pretty common for turbo cars to circulate coolant/run fan operation electronically for a period of time even after engine is shut off. Good peace of mind.

Just keep in mind that they DO NOT circulate oil after engine shut down, and that's the issue. The turbo can spin up around 3000 revolutions per SECOND at full throttle. If you do that and then shut the engine off moments later, it's likely that the turbo will still be spinning pretty fast, and without oil pressure, bearing life will suffer. Of course if you drive it gently, or even normally for a couple mins before shut down, the turbo will have time to drop to idle speed and the oil pressure drop won't be a factor.

Normally in real world use, you will typically go through a parking lot, or neighborhood before shutting off the car, that sort of forces you to let the turbo slow down a little, and after shut down, the coolant pump will do the rest, so this isn't really much of an issue.

Greg

 

[[email protected]]

I think I'll further clarify. The owner's manual for the 2.0 car has the following statement on page 131: "It is recommended before switching the vehicle off, to keep the engine idling for a few minutes so that the turbocharger can be suitably lubricated. LUBRICATED is the key word there. This has nothing to do with the coolant pump. That pump will not help with a lack of lubrication.

It goes on to say "This procedure is
particularly recommended after severe
driving.
After a full load operation, keep the engine
idling for three to five minutes before
switching it off.
This time allows the lubricating oil and the
engine coolant to eliminate the excessive
heat from combustion chamber, bearings,
inner components and turbocharger."

I think it's a good idea to follow these directions.

Greg

 

[AlfaAndy]

Just keep in mind that they DO NOT circulate oil after engine shut down, and that's the issue. The turbo can spin up around 3000 revolutions per SECOND at full throttle. If you do that and then shut the engine off moments later, it's likely that the turbo will still be spinning pretty fast, and without oil pressure, bearing life will suffer. Of course if you drive it gently, or even normally for a couple mins before shut down, the turbo will have time to drop to idle speed and the oil pressure drop won't be a factor.

Normally in real world use, you will typically go through a parking lot, or neighborhood before shutting off the car, that sort of forces you to let the turbo slow down a little, and after shut down, the coolant pump will do the rest, so this isn't really much of an issue.

Greg

If you want to do your best to increase longevity and reduce incidence of problems, for ANY internal combustion engine, it is best to allow a moment or two of idling before you shut off your engine, after it has been in use. For example, even my Cub Cadet lawn mower (with Kawasaki gas engine) states in the owner's manual that one should allow a full minute at idle, before shut off, after use. This is even more important for turbo engines, especially after arduous use such as spirited road driving, or track events.
I remember one explanation in particular, that was directed at turbo engines. Obviously, at full throttle and full boost (or even moderate pedal and boost), the turbo is spinning very fast because of the large amount of high temperature exhaust gases passing through it. The spinning shaft has a bearing that is lubricated with flowing pressurized engine oil. It also has lip (style) seals that keep the oil from leaking out. The shaft is connected to the vanes on both the exhaust and intake sides. The shaft (as well as many other parts) gets very hot. If you run that spinning shaft to full temp and then shut it off (without allowing it to come to idle and cool a bit), you can run the risk of having the oil (on the shaft, at the seal area) sear and bake onto the shaft. This baked-on debris, can then contribute to premature turbo shaft seal failure and leakage. By allowing the engine to idle for a moment or two, you are allowing the pressurized oil and flowing coolant to cool the unit and minimize this potential problem. How's THAT for a reason to allow a moment for cool-down!

 

[Il_Conte]

I always drive it very gentle at the beginning of the drive till it warms up and at the end for cooldown.

 

[ibehardnock2001]

I honestly wouldn't worry too much about cool down if you have not driven it hard. You have to consider the fact that the car is featuring auto stop/start technology and if enabled, the engine is turning off multiple times in any given trip anyway. So I am confident that AR has taken this into consideration when designing their turbo and cooling features.