I have noticed that my 2012 TSX SE 6-spd when sitting in traffic during hot days exhibits engine heat soak real bad. What I mean by that is the power drops off dramatically to the point where you have to press hard on the accelerator pedal just to get up to speed. You do have to be in stopped traffic for quite a while. But it becomes very easy to almost stall the engine. Although I have yet to stall it (probably due to the fact I have been driving manuals all my life).
So has anyone noticed this heat soak condition??

 

^most cars in general display heat soak during the summer months.
on the third gen TL side, we have innovated a little bit to relieve some of this heat soak.
this involves doing the coolant bypass mod, which re-routes your coolant so that it doesnt go through or pass the throttle body.

we've also alleviated some of the heat by cutting up the windshield cowl.
from the outside it would look normal.
But I do understand if you choose not to go this route as its a brand new car.

 

justnspace, I know what you mean all cars will exhibit some type of heat soak usually minor , I have owned several cars in my lifetime.
But my TSX 4-cylinder seems much more sensitive to it. If you look at the engine bay there is a ton of room. You would think there would be plenty of air flow around the engine. It also has a composite intake manifold.
Being a brand new car I thought I would ask if others have noticed this. The symptom is very noticeable on mine.
Eventually when the TSX is out of warranty (which will be a while) I will play with it.
On a different note I did perform the throttle body coolant bypass on my Corvette, although I must admit my Vette did not have this type of symptom.
I did it more for quicker ET's down the quarter mile.

 

I actually noticed this about two years ago the first time it exhibited symptoms. Thought it was an ECU problem at first. Would BARELY accelerate and you'd have to stop down on the gas to get it to even do that. And even at idle (mine being an AT) it had some problems and sputtered real bad a few times. Thought it was going to stall. We've had some pretty hot days since including this past summer but mostly it just comes down to crappy acceleration now. I quite happy it hasn't sputtered since the first time it did it. Thought I was headed to the dealer for a repair. But yeah, definitely not a great car in the heat. I've had other older cars including my famed '91 Stealth RT/TT AWD (with absolutely ZERO room in the engine bay for air) which never had cooling issues. Always ran hard even in the summer months. So it must be something with how the car perceives incoming air temperature. It obviously adjusts the a/f mix somewhere to a point where it is useless.

 

^it is an ECU problem.
Heat = reduced timing.

over on the 3G TL side, we've also monitored Intake air temperatures and its really important to keep them a little above ambient temp.
anything over 60 degrees above ambient KILLS performance.

with the cutting up of the cowl mod that I talked about earlier, air flows through the opening of the grill and over the intake manifold, cooling it down, while escaping above the windshield.