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cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to Kearnstd

Re: Engine missing after being at shop--what now?

said by Kearnstd:

Never knew that about turbos. Though maybe its variable per car. I have the turbo engine in my 2012 Cruze and the manual never mentioned sitting there idling for a bit.

It's pretty much any turbo. If you drive hard, the turbo can reach very high temperatures. If you shut down the engine, the oil lines that run through the turbocharger don't flow, so that heat cooks the oil. It's not a problem as much in the engine itself as the oil can drip down into the oil pan where it's not in direct contact with the heat.

You can get a turbo timer that will idle your car and allow things to cool down some while the oil is flowing around. Think of it kind of like a reverse cold weather remote starter. It runs the car for 10 or 15 minutes and then shuts down, but if someone tries to move it, get in, etc it shuts down immediately.

itguy05

join:2005-06-17
Carlisle, PA

1 recommendation

reply to Kearnstd
said by Kearnstd:

Never knew that about turbos. Though maybe its variable per car. I have the turbo engine in my 2012 Cruze and the manual never mentioned sitting there idling for a bit.

Depends on the car. I know with Ford's Ecoboost engines the turbo bearings (What get hot) are water cooled and do not need an idle down period. They circulate coolant around them and that will keep them cool when shut off.

From Ford directly:

"Designed for a life cycle of 150,000 miles or 10 years, EcoBoost’s turbochargers feature water-cooled bearing jackets. This architecture is designed to prevent oil “coking” that could occur in previous-generation turbochargers. The new design means that EcoBoost drivers don’t need to observe special operating precautions, such as idling the engine before switching it off."


VegasMan
Are We There Yet?
Premium
join:2002-11-17
Schaumburg, IL
itguy05 beat me to it. I was going to say the same thing.
--
In need of a Vegas vacation.


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Reviews:
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reply to itguy05
said by itguy05:

snipped marketing quote

That is technical advice written by the marketing department.

Idling for a period of time after engine shutdown under certain circumstances is still a very good idea.

After:
- pulling off the highway to buy gas,
- driving agressively
- driving under high load

Ask any technician with experience working on turbocharged cars.
--
The talented hawk speaks French.

Beezel

join:2008-12-15
Las Vegas, NV

1 edit
reply to itguy05
said by itguy05:

said by Kearnstd:

Never knew that about turbos. Though maybe its variable per car. I have the turbo engine in my 2012 Cruze and the manual never mentioned sitting there idling for a bit.

Depends on the car. I know with Ford's Ecoboost engines the turbo bearings (What get hot) are water cooled and do not need an idle down period. They circulate coolant around them and that will keep them cool when shut off.

From Ford directly:

"Designed for a life cycle of 150,000 miles or 10 years, EcoBoost’s turbochargers feature water-cooled bearing jackets. This architecture is designed to prevent oil “coking” that could occur in previous-generation turbochargers. The new design means that EcoBoost drivers don’t need to observe special operating precautions, such as idling the engine before switching it off."

Here is the real scenario that happens with turbos.

Turbos can spin in excess of 50,000+ RPM's. When it is spooled up "IE. making boost" the water does help keep the temps down and the oil keeps the bearing lubed (which is what helps keep it from destroying itself). But here is the kicker.

When you shut the engine off after acceleration and a quick stop, or rev the engine before just before shutdown (this is mostly for those with manual tranny's), the turbo keeps spinning until it stops after the engine is off. The speed at which the turbo was operating at before engine shutdown determines how long it will take the turbo impellers to stop spinning. "The slower the better" before shut off. When shut off and the turbo is still spinning down, not all cars are still circulating the coolant and/or oil to keep the bearings cool. This is where you run into short life spans. Even if your Ford has liquid cooled bearings does it still have a water pump circulating the coolant to the turbo, or a after oilier circulating oil to it? So it is still wise to wait a minute or several seconds before you shut the engine down, because not all cars have those function. My VW GTI has a secondary "timed" electric water pump just to pump the coolant to the turbo after shutdown. A nice feature but I still wait for the turbo to slow before shutting it off.

ke4pym
Premium
join:2004-07-24
Charlotte, NC
Reviews:
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reply to JAAulde
My 2000 Jetta had a secondary electric water pump that kept coolant flowing after the engine was off. And it was a non-turbo VR6.

Sadly, it just started costing too much money to keep up. Only had 86,000 miles on it when the front seat let go and turned into a rocking chair.

VW wanted $1k to fix, and I wasn't successful at finding a cheap replacement. Seems the 2000 GLXes were a rare breed.

Had a local euro shop weld it for $100. Sold the car, under full disclosure and was done with it.

Beezel

join:2008-12-15
Las Vegas, NV
said by ke4pym:

My 2000 Jetta had a secondary electric water pump that kept coolant flowing after the engine was off. And it was a non-turbo VR6.

Sadly, it just started costing too much money to keep up. Only had 86,000 miles on it when the front seat let go and turned into a rocking chair.

VW wanted $1k to fix, and I wasn't successful at finding a cheap replacement. Seems the 2000 GLXes were a rare breed.

Had a local euro shop weld it for $100. Sold the car, under full disclosure and was done with it.

Yea, I forgot that the VR6 had the secondary pump also, but after 1999 VW started to over build everything.

I have to replace the bottom seat foam in my GTI, but it has custom factory Recaro racing seats with side airbags. You need a special jumper harness that goes into the airbag wiring in the seat after you disconnect it. I am figuring it is so a static discharge won't make it go "pop".

But after you reconnect it to the system again you have to leave the ignition on while you hook the battery back up. This is the only air bag you need to do this to for some reason. :/ Oh well I may see what the dealer charges for it, versus buying the jumper and doing it myself.... Getting lazy at my old age. :P


EGeezer
zichrona livracha
Premium
join:2002-08-04
Midwest
kudos:8
reply to Beezel
I always thought there was some reason behind my desire to avoid turbocharged engines - the discussion pretty much quantified my instincts.
--
Buckle Up. It makes it harder for the aliens to suck you out of your car.


JAAulde
Web Developer
Premium,MVM
join:2001-05-09
Williamsport, MD
kudos:3
said by EGeezer:

I always thought there was some reason behind my desire to avoid turbocharged engines - the discussion pretty much quantified my instincts.

Something you had never heard of or considered was the reason behind your desire to stay away from turbocharged engines?
--
The Yakabox | My Development Sandbox | LinkedIn Profile


EGeezer
zichrona livracha
Premium
join:2002-08-04
Midwest
kudos:8
Reviews:
·Callcentric
said by JAAulde:

Something you had never heard of or considered was the reason behind your desire to stay away from turbocharged engines?

No, it's just that I'd heard very little of the specifics of increased maintenance, additional startup and shutdown needs and other issues.

I've avoided turbocharged engines because there were too many parts moving at too high speeds in too high temperatures and yielding too little benefit to me over normally aspirated engines.
--
Buckle Up. It makes it harder for the aliens to suck you out of your car.

Beezel

join:2008-12-15
Las Vegas, NV

1 recommendation

said by EGeezer:

said by JAAulde:

Something you had never heard of or considered was the reason behind your desire to stay away from turbocharged engines?

No, it's just that I'd heard very little of the specifics of increased maintenance, additional startup and shutdown needs and other issues.

I've avoided turbocharged engines because there were too many parts moving at too high speeds in too high temperatures and yielding too little benefit to me over normally aspirated engines.

Once you experience the added power and torque a turbo adds, then you might reconsider.

Turbos actually only have 1 major moving part. Two impeller blades joined by a common shaft (most common failure the bearings go or the shaft breaks). Then a waste gate that is regulated mechanically or electronically to help control the boost pressure.

There is another type of turbo (variable vane turbo's, the exhaust side impeller blade can change their pitch for added turbo RPM's to make more boost without requiring a increase in engine speed) but those are mainly used in heavy duty commercial situations. So those don't really apply to general automotive use.