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Discussion Starter · #1 · (Edited)
As more owners of other makes of cars buy Kias there are going to be more questions about the Intake Air Temperature (IAT) readings. Some of these new Kia owners will be information savvy and read their Kia's IATs and then post about how high their Kia's IATs are compared to their old (Insert: Chevy, Ford, Subaru, etc)!

Are the IATs high on Kias because Kia doesn't know how to build engines properly? Why did my Ford/Chevy/Subaru have IATs closer to the ambient temperature then my Kia does?

Lets look at the reason:

Other cars read their IATs at the Mass Air Flow (MAF) sensor. Where is the MAF sensor located? In the Intake tube right next to the Air Filter Box. It is reading the Air Temperature of the incoming air. That's it. It should be called the "Incoming Air Air Temperature" sensor...it has NOTHING to do with the intake manifold air temperature.

Kia has their IAT sensor in the Manifold Air Pressure (MAP) sensor located IN the Intake Manifold. Kias IAT sensor is reading the air temperature IN the intake Manifold. The air in the intake manifold is subjected to the heat soak of the intake manifold bolted to a hot engine, PCV air that has been heated to 190+ degrees in the crankcase, and intake air that was heated to 200+ degrees by a turbocharger and then cooled in the intercooler.

So in conclusion: Other makes of car do not provide the air temperature from inside the intake manifold while Kia does. Apples to Oranges comparison. Kia's engine information is actual and useful - the other manufacturers' engine information is not accurate and not useful.

Note: this is for entertainment. This website is not for information.
 

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Discussion Starter · #2 ·
If you think your turbocharged Kia's intake Air Temperature is high you should read the IATs of non-turbocharged Kias.
 

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Discussion Starter · #3 ·
duplicate post
 

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'21 GT Manual
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My concerns with high intake air temps aren't that the parts are going to melt or anything, it is with predetonation (Knocking/Pinging). Higher pressures and temperatures lead to spontaneous combustion or LSPI in the cylinders. These multiple detonation events can cause massive pressure spikes in the cylinder leading to long term issues. Tiny displacement turbo engines with a lot of tech (twin scroll turbo tuned for full boost at low RPM, variable valve timing and continuously variable valve duration, direct injection etc) are much more susceptible to these LSPI events than a naturally aspirated pushrod engine from not too long ago. 201HP is a lot of power to ask from an engine with less than 1.6L of displacement. It may be true that the sensors in other vehicles were located in a different area giving them a lower reading, but that does not mean that 149F is not absurdly hot air for the air/fuel mix going into the engine, especially at over twice atmospheric pressure.


 

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Discussion Starter · #5 ·
My concerns with high intake air temps aren't that the parts are going to melt or anything, it is with predetonation (Knocking/Pinging). Higher pressures and temperatures lead to spontaneous combustion or LSPI in the cylinders. These multiple detonation events can cause massive pressure spikes in the cylinder leading to long term issues. Tiny displacement turbo engines with a lot of tech (twin scroll turbo tuned for full boost at low RPM, variable valve timing and continuously variable valve duration, direct injection etc) are much more susceptible to these LSPI events than a naturally aspirated pushrod engine from not too long ago. 201HP is a lot of power to ask from an engine with less than 1.6L of displacement. It may be true that the sensors in other vehicles were located in a different area giving them a lower reading, but that does not mean that 149F is not absurdly hot air for the air/fuel mix going into the engine, especially at over twice atmospheric pressure.


There is NO DOUBT in my mind that Kia engineers are aware of the heat soak. As soon as you start driving the temperatures come down fast. Watching my IAT while driving, the red-light idle-heat-soak temperature is back to normal before I finish going through an intersection. No doubt the engine is pulling timing to prevent pre-ignition in this condition (Oops sounds familiar...we're getting into that Octane argument again - if you're concerned might want to up the octane level....HMMMMMM).

I also have no doubt that the idle-time-heat soak happens with every manufacturers turbocharged engine because there is no airflow through the intercooler. You just can't see this on other manufacturers cars' because they are reading their nice cool IATs at the air filter box.

Since Kia puts the IAT sensor in the intake of most of their cars - I found my Wife's '17 Optima non-turbo 2.4 goes into idle heat-soak mode too. Between 40 degrees and 50 degrees above ambient - and it takes a bit of driving before it comes down. Again, this is normal for ALL cars. People aren't aware of it because of the IAT sensor location - and most owners of Kias could care less...:).

...and remember - this is entertainment, not information.
 

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Are you trying to convince me it's not an issue? Or are you trying to convince yourself? I use 93 so I know it won't be an issue for me. Just going to leave this here.


83451
 

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Are you trying to convince me it's not an issue? Or are you trying to convince yourself?
No, I think he's trying to say that if you take the other Mfg's IAT sensor location and move it to the same area that Kia has theirs then the other Mfg's IAT temps will read just as Kia's.
 

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Discussion Starter · #8 · (Edited)
No, I think he's trying to say that if you take the other Mfg's IAT sensor location and move it to the same area that Kia has theirs then the other Mfg's IAT temps will read just as Kia's.
BINGO! You WIN!

:)

I've been seeing more posts complaining about their GT's IATs and comparing them to other cars they had. So I researched it and sure enough their other cars had IAT sensors in their MAF sensors located at the air filter box.
 

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Discussion Starter · #11 ·
Are you trying to convince me it's not an issue? Or are you trying to convince yourself? I use 93 so I know it won't be an issue for me. Just going to leave this here.


View attachment 83451
2013 is not 2020-2021.

All Kia has to do is relocate the IAT sensor to the air filter box like other manufacturers and the problem is solved...<sarcasm>

I'm glad Kia installed the IAT in the manifold - I like seeing the true engine data - good and not so good.
 

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BINGO! You WIN!

:)

I've been seeing more posts complaining about their GT's IATs and comparing them to other cars they had. So I researched it and sure enough their other cars had IAT sensors in their MAF sensors located at the air filter box.
Do you still have the links for the locations of these sensors? I've always been curious where they were located.

I believe the reason the vehicles I have had previously didn't exhibit the same heat soaking issue as quickly as the Kia, had to do with two things. Both of my other turbo vehicles had the exhaust coming out of the front of the engine and put the turbo behind the radiator, with the intake on the backside near the firewall. The GT is opposite, and has the turbo sitting behind the engine next to the firewall. The Kia also has a plastic aero shield that covers the entire bottom of the engine bay. Between that and the limited air flow behind the engine bay makes it very difficult for air to circulate around the extremely hot turbo. As a result, any time spent stationary causes heat to build up in all of the plumbing for the air, then it takes forever to get the IATs down. Most of the time, they will still hover right around 30-40F higher than ambient.


2013 is not 2020-2021.

All Kia has to do is relocate the IAT sensor to the air filter box like other manufacturers and the problem is solved...<sarcasm>

I'm glad Kia installed the IAT in the manifold - I like seeing the true engine data - good and not so good.
LPSI is a very real issue for all car manufacturers. Now that car companies are being forced to meet new incredibly strict EPA demands, small turbo engines that are being pushed to the absolute limit are becoming common. Car manufacturers have partnered with the petroleum industry to develop special engine oils and fuel additives with extra detergents that help keep carbon particles from getting into the cylinders, as the carbon can act as an ignition point for the fuel/air to spontaneously combust as it is being compressed.

This is a known issue for almost every small displacement turbo engine from every manufacturer. It was an issue on the very same engine they use in the GT a few years prior when Hyundai was using that Gamma 1.6L turbo in the Veloster. (Which is why I posted that link) How did they fix the issue? Software and sensors. The engine design is exactly the same, but now Hyundai have instructed the car's computer to de-tune itself and retard spark timing when the knock sensors detect pinging. This is so the engine doesn't suffer from sudden unexpected rapid disassembly.




 
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