Turbo cooling question

[peteexplores]

Hi all,

This is my first post in this forum since I just picked up my 2015 Explorer Sport. Actually this is the first non-pickup vehicle that I've owned since prior to about 1994. It's my previous ownership of two Powerstroke diesels that prompts this question. As a diesel owner it has always been drummed in my head that you never turn off a diesel while the turbo is hot. I had an Insight gauge to measure exhaust gas temps and I did not shut the truck down until those temps came down to around 300 degrees. What occurs to me though is that I have never heard the same warning about turbo'd gas engines. Should I be treating my 3.5 L Ecoboost with the same kid gloves? If so, why is there no mention of this anywhere in the manuals? Any info would be appreciated.

 

[peterk9]

Welcome to the Forum peteexplores.:wavey:
The Ecoboost engine has been in the Explorer Sport since the 2013 model year and I don't recall anyone bringing this issue up before. I don't do anything different with mine as opposed to a N/A engine when turning the vehicle off.

Peter

 

[1995E]

I googled and found this concern with turbochargers:

"Following a hot shutdown of a turbocharger, heat soak begins. This means that the heat in the head, exhaust manifold, and turbine housing finds it way to the turbo’s center housing, raising its temperature. These extreme temperatures in the center housing can result in oil coking.
To minimize the effects of heat soak-back, water-cooled center housings were introduced. These use coolant from the engine to act as a heat sink after engine shutdown, preventing the oil from coking. The water lines utilize a thermal siphon effect to reduce the peak heat soak-back temperature after key-off"
http://skeptics.stackexchange.com/q...-charged-engine-require-a-cooling-down-period

I am not sure if the turbos on the Ecoboost motors are water cooled or not. Maybe that would answer your question if you found that out.

 

[peteexplores]

Yep, it's that coking of the oil in the turbo that people speak of in the diesel turbo. The idea is that you leave the engine on long enough for the oil to get down to a reasonable temperature. Maybe it is the water cooling but then I have to go back to the question about why it is a concern in the diesel and not here. Why would the turbo designs be different?

I might turn around and ask that question of my old diesel forum friends too. Anyway, thanks for the responses guys.

 

[GSX-WE4]

I've had an 87 Turbo Regal since new and after any spirited driving or racing at the track, I let the car idle for a minute or so before shutting the engine off. Using synthetic oil is the best way to go to prevent any oil "cooking" issue.

 

[Fpo]

Using synthetic oil is the best way to go to prevent any oil "cooking" issue.

Yes but it is "coking"

the heat will easily turn a conventional oil to "coke"

http://www.machinerylubrication.com/Read/23715/conventional-vs-synthetic-oil

 

[GSX-WE4]

Yes but it is "coking"

the heat will easily turn a conventional oil to "coke"

http://www.machinerylubrication.com/Read/23715/conventional-vs-synthetic-oil

"Typo"

 

[peteexplores]

So it sounds like I'm hearing at least some agreement that it is a good idea. But, having said that, I'm surprised it is not a bigger issue. Coking in the turbo is a significant issue. And given that almost nobody seems to be aware of it, why do we not see more problems related to that?

 

[Fpo]

"Typo"

Gotcha

I used to work at ExxonMobil, in the coker unit.
The waste is basically "cooked" until it is in solid form, so the coke is cooked

Another thing to consider ...
Using lower quality oil (Not Full Synthetic oil)
will have a higher NOACK Volatility
""The NOACK Volatility Test, otherwise known as ASTM D-5800, determines the evaporation loss of lubricants in high-temperature service.[1] The more motor oils vaporize, the thicker and heavier they become, contributing to poor circulation, reduced fuel economy and increased oil consumption, wear and emissions."" source http://en.wikipedia.org/wiki/NOACK_Volatility_Test


That burned off stuff has to go somewhere.

I had bad fuel dilution on the oil sample I took when my Sport had the oil the Steelership used to service it.

I have since upgraded the oil and will take another sample at about the same interval.
I will share the results here.

 

[Sinister-CO]

The turbos on the ecoboost engines are water cooled and do not require any cool down time due to the thermal siphoning mentioned above. The turbo Buicks of the 80's did need some spin down time as the only cooling they had was via the oil itself. I also never shut my GN down after running it hard without a moment or two of idle time.
Now all that being said, it if makes you more comfortable letting these little twins spin down and cool a bit before shutting it off, obviously that's not going to hurt anything. I can't speak to diesels as I've never had one. I would assume the same goes for them though. If they're water cooled they're going to be more tolerant of that heat due to the thermal siphoning.

 

[peteexplores]

The turbos on the ecoboost engines are water cooled and do not require any cool down time due to the thermal siphoning mentioned above. The turbo Buicks of the 80's did need some spin down time as the only cooling they had was via the oil itself. I also never shut my GN down after running it hard without a moment or two of idle time.
Now all that being said, it if makes you more comfortable letting these little twins spin down and cool a bit before shutting it off, obviously that's not going to hurt anything. I can't speak to diesels as I've never had one. I would assume the same goes for them though. If they're water cooled they're going to be more tolerant of that heat due to the thermal siphoning.

I also got the following information from someone on the diesel forum which supports this idea:

Found this article on the 3.5 Ecoboost with the following comment.

The EcoBoost approach eliminates several customer worries from previous turbocharger applications. Designed for long-life reliability, 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. The turbochargers are designed for a life cycle of at least 150,000 miles or 10 years.

 

[expoman55]

Turbo cool down

I know this is an old thread but bear with me please.. I am new to this generation explorer for only a week and I notice my fans shut off with the vehicle ignition. I am not used to this as all my previous Turbo ( non diesel ) cars have always had a cool down circuit and run the fans for a few minutes to cool down the turbos.

Has anyone done this to an X? I hope to have this new sport for a LONG time.

Thanks..

Oh and if I built a small circuit to do this myself would I void the warranty?

 

[explosportguy]

I know this is an old thread but bear with me please.. I am new to this generation explorer for only a week and I notice my fans shut off with the vehicle ignition. I am not used to this as all my previous Turbo ( non diesel ) cars have always had a cool down circuit and run the fans for a few minutes to cool down the turbos.

Has anyone done this to an X? I hope to have this new sport for a LONG time.

Thanks..

Oh and if I built a small circuit to do this myself would I void the warranty?

My XKR supercharged engine had a cool down with fans running even though there were no spin down issues. I fried a turbo in my 924s (no water cooling circuit) but never a problem with the water cooled turbo in my 944T. Still, out of habit I let my xsport settle for 30 sec or so at idle before I shut it down. Probably not necessary but I do it out of habit.

IMHO most likely no need to build the cooling curcuit for the XSport. It seems engine longevity is one of the things Ford got right.

 

[tsilney]

I know this is an old thread but bear with me please.. I am new to this generation explorer for only a week and I notice my fans shut off with the vehicle ignition. I am not used to this as all my previous Turbo ( non diesel ) cars have always had a cool down circuit and run the fans for a few minutes to cool down the turbos.

Has anyone done this to an X? I hope to have this new sport for a LONG time.

Thanks..

Oh and if I built a small circuit to do this myself would I void the warranty?

My 2015 sport runs the fans after ignition is turned off for like 30 Seconds...

 

[orangesoda123]

I'm assuming the the ecoboost explorers are similar to the F-150s. The F-150s will continue to cycle coolant through the turbos even after the vehicle is off for a few minutes to help bring the temp down. I'm assuming the Ex's do the exact same thing.

As for the fans after shutting off the vehicle, has anyone noticed if they stay on depending on how hard you've been to the vehicle? I'm wondering if they are below a certain temp they won't bother to stay on.

Anyways I wouldn't bother with any aftermarket turbo timers or anything of the sort. They were designed with being able to shut down normally in mind.

 

[expoman55]

Hello everyone, years ago I had a Turbo z car that had a delay on the radiator fan that would allow it to continue to run for a determined period of time after the car is shut down. I was told this was to continue to cool under the hood especially the turbos to keep the oil from boiling while just sitting still after shutting it down after a drive. Does anyone make a plug an play kit for the exploder? I have a 15 Tuned sport. .

 

[peterk9]

As indicated, your thread has been merged with this one. In reading the posts above, it seems your concern is not one to worry about.

Peter

 

[182RG]

Hello everyone, years ago I had a Turbo z car that had a delay on the radiator fan that would allow it to continue to run for a determined period of time after the car is shut down. I was told this was to continue to cool under the hood especially the turbos to keep the oil from boiling while just sitting still after shutting it down after a drive. Does anyone make a plug an play kit for the exploder? I have a 15 Tuned sport. .

Not necessary.

During the R&D process, Ford engineers ran the EcoBoost at WOT for 10 minutes, then abruptly shut the motor down to halt the flow of oil and coolant to the turbos. This test-in which the turbos hit temperatures of nearly 1,800 degrees F-was repeated 1,500 times without once changing the oil. Upon disassembling the turbos afterward, the bearings showed no signs of abnormal wear. "Every 10 minutes, the test alternates between peak power at max exhaust temperature, and completely cold motoring," explains Keith Plagens, Ford turbo systems engineer. "The goal is to verify that the turbochargers can withstand extreme thermal cycling without affecting their performance...

http://www.hotrod.com/how-to/engine/0910phr-ford-ecoboost-six-cylinder/

 

[Fentress24]

This is good information. Before water cooled turbo's I used a turbo timer and would set it for 30sec-2minutes depending on how hard the car was driven.

My fan will run after the car is turned off if the truck is hot. With this 90+degree days the last couple weeks I have noticed it keeps running pretty often.

 

[BMan5150]

My fans also run for a 30 seconds or so after running the car. Seems possibly to do so more in the summer heat, which makes sense.