# Turbo need to be cooled?



## tehcor (Mar 30, 2011)

aftereffects said:


> I heard that turbos in a car need to be cooled down after a trip, but I wasnt sure if this applied to the cruze? I have been leaving the car on for a couple of minutes after a drive, but do I really need to?
> 
> Thanks.


Our turbos are oil and liquid cooled also which prevents the oil "cooking" as it does with cars that arent liquid cooled.I let mine cool down for bout 30-45 secs after hard driving just to be sure tho


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## CHEVYCRUZE RS (Mar 29, 2011)

nice call tehcor


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## 70AARCUDA (Nov 14, 2010)

...just to add what *tehcor* posted, the electronically-controlled thermostat in the Cruze allows the engine control module (ECM "brain") to adjust/change thermostat operation to meet _different_ cooling needs; specifically, it lets the engine run *hotter* for better fuel *economy* when under _light_ load, and then run *cooler* for better *cooling* (and longer engine & turbo life) when under _heavy_ load.

...curiously, those changes in thermostat temperatures don't seem to show-up on the dash gauge at all.


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## Skilz10179 (Mar 22, 2011)

A good rule of thumb is to try to stay out of boost the last couple minutes of drive. This will keep exhaust gas temperatures lower which is what causes a turbocharger to get hot.

If you're really concerned about it you can always install a turbo timer.


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## aftereffects (Apr 4, 2011)

So I pretty much dont need to worry about it then?


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## usaalways (Mar 29, 2011)

tehcor said:


> Our turbos are oil and liquid cooled also which prevents the oil "cooking" as it does with cars that arent liquid cooled.I let mine cool down for bout 30-45 secs after hard driving just to be sure tho


 Does this mean you just let the Cruze idle before turning it off?


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## tehcor (Mar 30, 2011)

Skilz10179 said:


> A good rule of thumb is to try to stay out of boost the last couple minutes of drive. This will keep exhaust gas temperatures lower which is what causes a turbocharger to get hot.
> 
> If you're really concerned about it you can always install a turbo timer.


Actually it's so the hot oil that is cooling down your turbo doesn't get left in the housing.then gets shut off and sits there and pools up and "cooks"
But yes..a turbo timer is a alternative or since as was already stated our turbo is liquid cooled which means it can't cook in there very easily.just wait 30 secs before shutting off.gives the oil enough time to cycle out of the turbo.


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## tehcor (Mar 30, 2011)

usaalways said:


> Does this mean you just let the Cruze idle before turning it off?


Yup just let it idle for 30 secs


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## usaalways (Mar 29, 2011)

tehcor said:


> Yup just let it idle for 30 secs


Thanx for the simple response and not bashing me. Im a person who knows nothing about turbo. Heck if mine didnt work Im not sure I wouldn't notice, since Im one who drives like grandma(Im a 36 yr old male by the way). I dont think I ever toko my ECO above 4,000 RPMs in my 3+weeks of having it. LOL
Just got my ECO for fuel economy and something NEW to drive after 10 yrs of driving a stripped Sephia.


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## tehcor (Mar 30, 2011)

Lol gotta learn one way or another.very good question compared to some I've seen on here.regardless of how high you rev it..it's gonna spool everytime you drive so unless it's a absolute emergency just give it time to cool.better than having to be without a car cause your turbo is cooked together.


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## SilverCruzer (Nov 30, 2010)

70AARCUDA said:


> ...curiously, those changes in thermostat temperatures don't seem to show-up on the dash gauge at all.


Couldn't you infer from that it works? For example, if that ECM control was not there, then driving in light conditions you might see the temp gauge on the cool side, and loaded up you might see the temp gauge on the hot side. Now with the adustments, it puts both senerios at "normal".


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## 72buickgs (Mar 20, 2011)

very few people would ever realize that a turbo does require some short period of idling before engine shutdown. years ago, u had to idle a turboed vehicle for several minutes before engine shutdown.
in the 80's when the t-bird was available with the turboed 4 cyl (2.3L ?), u had to use a "turbo" compatible engine oil.


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## tehcor (Mar 30, 2011)

72buickgs said:


> very few people would ever realize that a turbo does require some short period of idling before engine shutdown. years ago, u had to idle a turboed vehicle for several minutes before engine shutdown.
> in the 80's when the t-bird was available with the turboed 4 cyl (2.3L ?), u had to use a "turbo" compatible engine oil.


Lol grand nationals were the same way but with v8's.


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## Skilz10179 (Mar 22, 2011)

tehcor said:


> Lol grand nationals were the same way but with v8's.


V8's?


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## tehcor (Mar 30, 2011)

Lol I didn't realize I put v8...I meant v6.


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## Skilz10179 (Mar 22, 2011)

tehcor said:


> Lol I didn't realize I put v8...I meant v6.


I figured you just made a mistake but i felt like Justin your balls lol!


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## tehcor (Mar 30, 2011)

Skilz10179 said:


> I figured you just made a mistake but i felt like Justin your balls lol!


Lol I was postin from my phone so mistakes slip by easily


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## Skilz10179 (Mar 22, 2011)

tehcor said:


> Lol I was postin from my phone so mistakes slip by easily


Lol i just realized my phone changed bustin to justin on my last post.


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## tehcor (Mar 30, 2011)

Skilz10179 said:


> Lol i just realized my phone changed bustin to justin on my last post.


See...you understand my pain lol


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## zz_cro (Apr 22, 2011)

Imagine this...turbo is driven by exhaust gases and it spins at much higher RPM than the engine. Its bearings are lubricated by circulating engine oil pumped by the engine oil pump trough them. If you rev the engine higher that would cause the turbo to spin faster (RPMs vary from turbo to turbo and it also depends of the engine load)...i am sure my numbers are off but for arguments sake let's say 30 000 RPMs...and then you shut down the engine...Engine stops...oil pump stops...no oil pressure left...only remaining oil left in places...and since turbo takes a bit longer to stop it still spins for a little bit longer without oil pressure...the higher RPMs were before shut down the longer the turbo is going to take to stop.


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## tehcor (Mar 30, 2011)

You just repeated essentialy what I already said..congrats.


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## Skilz10179 (Mar 22, 2011)

zz_cro said:


> Imagine this...turbo is driven by exhaust gases and it spins at much higher RPM than the engine. Its bearings are lubricated by circulating engine oil pumped by the engine oil pump trough them. If you rev the engine higher that would cause the turbo to spin faster (RPMs vary from turbo to turbo and it also depends of the engine load)...i am sure my numbers are off but for arguments sake let's say 30 000 RPMs...and then you shut down the engine...Engine stops...oil pump stops...no oil pressure left...only remaining oil left in places...and since turbo takes a bit longer to stop it still spins for a little bit longer without oil pressure...the higher RPMs were before shut down the longer the turbo is going to take to stop.


When the turbo is producing max boost its spinning 130,000+ rpm but it won't stay spinning like that long after the throttle closes, maybe a few seconds before it slows down to its idle speed rpm. Letting a car idle after driving is just to let things cool down before the ignition is turned off and the oil stops pumping.


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## Silphion (Mar 31, 2011)

Unfortunately the owner's manual sheds no light on this issue. It does make mention of various "Engine Overheated" messages, at which point it advises you to stop and let the engine idle. Other that, not even a mention of the turbo is found, let alone letting it cool.


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## Big Tom (Mar 8, 2011)

The 30 second rule sounds like an easy thing to live with and it won't hurt.


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## Big Tom (Mar 8, 2011)

Back when I drove a truck it was advised to idle for 3 min or until the exhaust gas temperature (EGT) pyrometer showed less than 250 degrees.


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## tehcor (Mar 30, 2011)

Big Tom said:


> Back when I drove a truck it was advised to idle for 3 min or until the exhaust gas temperature (EGT) pyrometer showed less than 250 degrees.


Egt gauge is a good thing to have but not really necessary..we don't have gt42r's in our car lol.they're small enough to cool quickly


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## 70AARCUDA (Nov 14, 2010)

...actually, with the turbine actually being positioned "inside" the exhaust manifold immediately adjacent the block, the normal block & manifold "heat" are going to be almost constant at around 400ºF, and only climb higher when under heavy load for long periods (which is *why* the ECM controls thermostat "temp" differently to produce light and heavy engine "cooling" temperatures).

...I'd say the "30-second idle" rule is 100% valid for drag races and stop-light blasts where it's "full-throttle" and "stop," but when driven typically & normally "on-the-street" just the slowing down as you drive up the street to your house and then onto your driveway would be more than sufficient.


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## Silphion (Mar 31, 2011)

Agreed on the city driving bit. But what about road trips? Would driving non-stop for four hours at highway speeds be considered a heavy load on the engine, or at least build quite a bit of heat? (Especially in the summer).


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## 70AARCUDA (Nov 14, 2010)

...I've never seen a freeway that didn't have a slower-speed off-ramp before you get onto the frontage roads for gasoline & potty stops.

...that slowing down should be fine, remember you're not driving the car at "full-throttle" even at 70-75 MPH, and all during that time, the ECM has been controlling the thermostat to keep engine operating (coolant & oil) temperatures "within" their specifications. If something goes "wrong", yes, it could be a problem, but not under normal & prudent driving conditions.


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## tehcor (Mar 30, 2011)

^ what he said lol

Unless you go into your driveway at 40 mph in 2nd gear you'll be fine.plus as it's been stated 20x our turbos are liquid cooled also.


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## MikeW (Nov 29, 2010)

70AARCUDA said:


> ...I'd say the "30-second idle" rule is 100% valid for drag races and stop-light blasts where it's "full-throttle" and "stop," but when driven typically & normally "on-the-street" just the slowing down as you drive up the street to your house and then onto your driveway would be more than sufficient.


Absolutely. This is a low-$20K compact car produced for the masses that doesn't ever care to even begin to understand anything about how it works. As such, the design team likely took that into consideration and the turbo will likely last the life of the car with no extra attention required. As for me, I will pull into my garage and shut it off. I have little worry that it will cause any problems for the 5 or so years I plan to keep the car.


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## tehcor (Mar 30, 2011)

MikeW said:


> Absolutely. This is a low-$20K compact car produced for the masses that doesn't ever care to even begin to understand anything about how it works. As such, the design team likely took that into consideration and the turbo will likely last the life of the car with no extra attention required. As for me, I will pull into my garage and shut it off. I have little worry that it will cause any problems for the 5 or so years I plan to keep the car.


Word.and if you're turbo does sieze just means it's time to go bigger


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## existensil (Apr 13, 2011)

I think it's also worth noting that the liquid cooling system is (like in most modern cars/motorcycles) capable of continuing to run AFTER the ignition is off, so if you DO squeel into your driveway at 5000rpm after some seriously heavy driving on a super hot day... I still think you'll be fine turning the car off immediately (well, let it at least return to idle for a split second). If there is excess heat the liquid cooling system and associated fans will remain on and _should_ prevent any cooking.

I don't plan to ever do this, I'm just pretty certain the engineers made sure shutting off your car too soon isn't going to break your turbo.


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## 70AARCUDA (Nov 14, 2010)

...BEFORE anyone tries to _"...nail..."_ *existensil*'s *Jello*™ to the wall for his statement:

_"I think it's also worth noting that the liquid cooling system is (like in most modern cars/motorcycles) capable of continuing to run AFTER the ignition is off..."_

...yes, the Cruze has a _mechancial_ water pump, not electric, so technically it can't be "pumping" coolant when the engine's OFF...however, the coolant can/does STILL "circulate" somewhat via the physics of "*themosiphoning*."


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