Quick question about IAT's and heatsoak

[ice445]

This is 100% normal. I see cylinder head temps like that all the time. I logged it, and the computer closes the grille shutters when you're sitting idle for some reason. If you turn on the A/C, they will quickly drop to under 200. If they don't, then maybe you have a problem.

IAT is partially affected by this, but mostly because the engine heat now has nowhere to go besides those tiny extractors when the shutters are closed. Stock intake does a bit better in general because the plastic is thicker.

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[MurphGT]

ya think it might have something to do with your MAF sensor (which contains your IAT sensor) being like 2 inches from your radiator now with a whole bunch of plastic surrounding it now?

yours is where the green dot is. this is stock, the blue dot.
red lines are radiant heat.

This is very helpful. Should I move the sensor (if that's even a thing)?

Basically the conclusion i've reached, based on feedback from multiple people is:
1) The sensor location being the reason for it showing high IATS
2) The lund tune turning on the fans early and often, causing the engine heat to be blown directly onto the sensor (and potentially into the airbox) ; People were saying installing the 170 T stat thermometer can help reduce the amount of time the fans are on

I asked lund if there's anything we can do with the tune to reduce IATs. They told me theyre not changing anything and that I would need to replace my Roush CAI. So basically it sounds like I need a 170 t stat, or to move the sensor?

 

[ice445]

This is very helpful. Should I move the sensor (if that's even a thing)?

Basically the conclusion i've reached, based on feedback from multiple people is:
1) The sensor location being the reason for it showing high IATS
2) The lund tune turning on the fans early and often, causing the engine heat to be blown directly onto the sensor (and potentially into the airbox) ; People were saying installing the 170 T stat thermometer can help reduce the amount of time the fans are on

I asked lund if there's anything we can do with the tune to reduce IATs. They told me theyre not changing anything and that I would need to replace my Roush CAI. So basically it sounds like I need a 170 t stat, or to move the sensor?

A 170 would help if Lund messed with the fan settings in the tune to make them come on at a lower temperature. If you drop in a 170 with stock fan profiles, you gain no benefit except at steady state cruise. I'm curious if he does anything about the stupid ass shutters on these cars with his tuning as well.

I don't really think the sensor location has much to do with it, the element that reads temp is directly in the airflow stream of the tube. There's some heat soak through the plastic, but not that much.

 

[Oakley]

This is very helpful. Should I move the sensor (if that's even a thing)?

Basically the conclusion i've reached, based on feedback from multiple people is:
1) The sensor location being the reason for it showing high IATS
2) The lund tune turning on the fans early and often, causing the engine heat to be blown directly onto the sensor (and potentially into the airbox) ; People were saying installing the 170 T stat thermometer can help reduce the amount of time the fans are on

I asked lund if there's anything we can do with the tune to reduce IATs. They told me theyre not changing anything and that I would need to replace my Roush CAI. So basically it sounds like I need a 170 t stat, or to move the sensor?

as with most things this is likely a combo.

1. not sealed box
2. right above the 200 degree radiator
3. plastic shielding/location preventing airflow

 

[babrams3]

Same setup as you and also in Florida.....I've never seen cylinder head temps above 208 and IAT's over 150 at idle. Both city and distance highway driving even on the hottest days down here

 

[Linkster1666]

Just FYI. When you have a hot engine, and other factors as said above, when you stop there is no place for the heat to go, so the IAT is going to sky rocket. 130*F in the Mojave your IAT is around 140 moving 45-50 mph. Heat soak, sitting, I've seen 190-200 in traffic at the peak of summer. Asphalt runs around 180* then.

Now, if your IAT is 200*F when you are moving 65 mph for a while, that is an issue.

 

[KingKona]

Perfectly normal to see IATs even above 200. If it's a blazing hot day, and you're sitting in traffic running the A/C, that's what's going to happen.

Relax, your car is fine.

 

[Zrussian13]

I ran a jlt and I don't think I ever saw 170s. I know it would get up in the 140s idling in long drive thrus or really bad traffic and 150s if I shut it off after heatsoaking it then started it back up. This all occurred in AZ summers though so maybe our dry heat isn't as bad as your mild humid FL ones!

 

[KingKona]

I ran a jlt and I don't think I ever saw 170s. I know it would get up in the 140s idling in long drive thrus or really bad traffic and 150s if I shut it off after heatsoaking it then started it back up. This all occurred in AZ summers though so maybe our dry heat isn't as bad as your mild humid FL ones!

What you think is "bad traffic" isn't.

There's far, faaaar worse out there.

 

[NightmareMoon]

dang. I'm NA too.

All I have is a Roush CAI and roush catback exhaust system. The only thing I changed today was going from stock tune to a Lund 93 octane tune. I might reflash back to stock tommorow and do some testing to see if the tune is maybe causing it?

Congratulations, you have a cold hot air intake. Open "CAI" intakes will do this. Its why most cars have closed boxes which route cool fresh air from the grill. Open cold hot air intakes generally suck air from the engine bay which is pretty hot from the engine, headers, radiator, etc when you're stopped.

Closed boxes which route from the grill are generally better, but maaaay not quite flow as much on the top end (depending on the design).

Once you're moving its a bit less of a problem, because the engine bay is getting washed with cooler air from the road, but yeah. Its one of the many cases where 'upgraded' parts are not necessarily better.

You can DIY a lid for the roush CAI and try to seal it off from everywhere but the grill, and it will get better.

 

[NightmareMoon]

This is very helpful. Should I move the sensor (if that's even a thing)?

Basically the conclusion i've reached, based on feedback from multiple people is:
1) The sensor location being the reason for it showing high IATS
2) The lund tune turning on the fans early and often, causing the engine heat to be blown directly onto the sensor (and potentially into the airbox) ; People were saying installing the 170 T stat thermometer can help reduce the amount of time the fans are on

I asked lund if there's anything we can do with the tune to reduce IATs. They told me theyre not changing anything and that I would need to replace my Roush CAI. So basically it sounds like I need a 170 t stat, or to move the sensor?

The MAF is NOT a temp sensor, and its not your problem at all. its a flow sensor for airflow inside that tube.. Its very particular about where it's located in that air stream. Don't mess with it.

 

[KingKona]

This is very helpful. Should I move the sensor (if that's even a thing)?

Basically the conclusion i've reached, based on feedback from multiple people is:
1) The sensor location being the reason for it showing high IATS
2) The lund tune turning on the fans early and often, causing the engine heat to be blown directly onto the sensor (and potentially into the airbox) ; People were saying installing the 170 T stat thermometer can help reduce the amount of time the fans are on

I asked lund if there's anything we can do with the tune to reduce IATs. They told me theyre not changing anything and that I would need to replace my Roush CAI. So basically it sounds like I need a 170 t stat, or to move the sensor?

Do nothing. Your car is fine.

If you do anything, simply re-install the factory CAI.

 

[Zrussian13]

What you think is "bad traffic" isn't.

There's far, faaaar worse out there.

Very true. I could be driving in virgina with all those douche bag drivers.

 

[Cory S]

WOT IAT is only what matters. Ford should have never allowed the average driver to monitor them. FWIW, hotter IAT while cruising can increase fuel economy.

 

[KingKona]

...FWIW, hotter IAT while cruising can increase fuel economy.

I'm pretty certain that's not factually correct.

Perhaps under certain specific circumstances it can, but usually it doesn't. It robs everything to do with power and economy.

Cooler air is denser and carries more oxygen.

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