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I noticed the oil temp drops about 15 to 20 degrees when I run in "sport" mode. Is that normal and if so, why?

Thanks
Ed
 

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That is the way mine runs. I don't know why. But it is a reason you need to run in non-sport mode once in a while to boil off any water/moisture that might get in the crank case or oil.
 

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I noticed the oil temp drops about 15 to 20 degrees when I run in "sport" mode. Is that normal and if so, why?

Thanks
Ed
Perfectly normal and my understanding is that an oil cooler is put online when sport/sport+ is enabled. Helps keep the oil from overheating during hard driving like on a track.
 

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Perfectly normal and my understanding is that an oil cooler is put online when sport/sport+ is enabled. Helps keep the oil from overheating during hard driving like on a track.
Wow. That’s good to know. #tmyk
 

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Perfectly normal and my understanding is that an oil cooler is put online when sport/sport+ is enabled. Helps keep the oil from overheating during hard driving like on a track.
If you have Sport+ it also activates the center radiator.
 

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If you have Sport+ it also activates the center radiator.
Not sure about that. My 2013 Boxster S doesn't have a central radiator. And yes I have sport/Sport+
 

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When you switch to Sport/Sport+ modes several things happen to enhance the engine and PDK cooling. First, the ECU controlled thermostat opens valves to route the engine coolant to the front radiators. Note that the front center radiator has no special valves controlling flow thru it. The center radiator is plumbed in line with the front right and left units. Also, when running in the Sport/Sport+ modes the ECU controlled thermostat sets the engine coolant temp at approx. 185 F. In non-Sport/Sport+ mode the thermostat sets the engine coolant at approx. 218 F. The ecu also controls the coolant gauge to show a steady 194 F approx irregardless of what the actual temp is. Not sure why Porsche chose to do that but it is what it is. You can see the actual coolant temps via an OBD port reader in real time. One more thing, the engine oil temp is also reflective of the engine coolant temp and if your vehicle has an oil temp gauge you can observe that dropping along with coolant temp when switching to the Sport/Sport+ modes. There are very detailed descriptions of all of this in various Porsche documents. The engine and transmission thermal control system for our vehicles is pretty complex actually.
 

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Not sure why Porsche chose to do that but it is what it is....
I believe higher engine operating temps in non-Sport/Sport+ mode has to do with meeting emissions requirements, however, another thought that came to me while writing this post (which I have no substantiation for) is that it may have something to do with reducing carbon buildup on the valves from the DFI. Also, if you switch to Sport/Sport+ mode before the engine reaches the higher operating temp, the ECU will not activate the lower temp setting until the engine reaches ~218 F.
 

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@vipereverything you wrote makes sense except the opening of the valves to the front radiators. That implies there are rear radiators, which I don't think is correct.
 

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Here is some information from the Cayman 981 GT4 Technical document that may shed some light onto the matter.
 

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The part about routing the cooling to the front radiators was a little confusing as written, but was essentially saying the thermostat opens to allow coolant to go the radiators just like all cars. Just a minor clarification, the radiators are not "in line" which would mean the coolant flows through all three radiators during a single pass (ie, through radiator 1 to 2 to 3), rather they are parallel so the coolant flows through a single radiator (choice of 3) before returning to the engine. Thanks for posting the dialogue and the PDFs while the diagram was most beneficial. I would assume this applies to GTS as well.
 
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My understanding is that the nonsport mode higher temperatures are also for better gas mileage as well as emissions. Hotter oil is thinner, so less drag and more efficiency.
 

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That is the way mine runs. I don't know why. But it is a reason you need to run in non-sport mode once in a while to boil off any water/moisture that might get in the crank case or oil.
If you can support your statement with some research I might consider it. Otherwise I think that’s the most ridiculous thing I’ve ever heard.
 

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Well let’s see. In sport mode my car reads 194°. In non sport mode it reads 227°. Recognizing that these are Porsche’s electronic readings and may not reflect actual temperatures, let’s postulate that the are roughly accurate.

Past research indicates that water boils at various temperatures, but is generally assumed to boil at 212° at sea level. (I refer you to the esteemed scientific journal “Wikipedia”. See HPS: The Myth of the Boiling Point). 227° being generally agreed to be in excess of 212° while 194° is generally agreed to be less than 212° would indicate that non sport mode would likely boil off any water in the crankcase from
condensation while sport mode would not.

I did seek funding from the CDC for a more definitive study, but they’re busy with more important things. Weissach would not allow me access to their research.
 

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Not to hijack, however this topic is quite relative to an issue I had this past weekend with a p1433 Front Coolant Fault that came about after very spirited mountain driving.

Could this be a result of a valve failure or oil cooler issue? Cleared the fault and it returned numerous times, though no temps got beyond ‘normal’ thresholds. 450 mile trip home with no fault. I’ve searched and found little real info.

Please PM if this comment needs to be taken to its own thread.

Thanks


Sent from my iPhone using Tapatalk
 

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Re to water/moisture being boiled off topic - it may be helpful to add that once the boiling point is reached, the resultant moisture/steam is then drawn out of the engine via the Positive Crankcase Ventilation (PCV) system which then routes it to the intake system where it is burned w/ the fuel/air and the exits via the exhaust. Prior to the entering the intake system is goes through Porsche's Air Oil Separator (AOS) which captures oil so that oil does not enter the intake. If you ever replaced an oil clogged PCV filter device, you will note there is often a milky gunk indicative of the water/moisture that was in the crankcase.
 

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Re to water/moisture being boiled off topic - it may be helpful to add that once the boiling point is reached, the resultant moisture/steam is then drawn out of the engine via the Positive Crankcase Ventilation (PCV) system which then routes it to the intake system where it is burned w/ the fuel/air and the exits via the exhaust. Prior to the entering the intake system is goes through Porsche's Air Oil Separator (AOS) which captures oil so that oil does not enter the intake. If you ever replaced an oil clogged PCV filter device, you will note there is often a milky gunk indicative of the water/moisture that was in the crankcase.
Good information, thanks everyone. But some of this boiling conversation needs clarification. Remember water that is under pressure has a higher boiling point. ie, water boiled at sea level boils at 212 degrees F. At 6,500' it boils at 200 degrees F. With our coolant systems pressurized to around 20 psi the boiling point of straight water would be something north of 212 degrees. Also the coolant fluid such as we use in our cars also raises the boiling temp. to approximately 256 degrees to 260 degrees at 20 psi. Having said all that when heated the coolant fluid does off gas. That is why we sometimes get the smell of antifreeze coolant when we shut our cars down after driving in the non sport normal mode.
 
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