Hey guys, I have an 08 TSX w/ a 5AT; yesterday I noticed something really weird while on the highway, when the transmission and cruising around ~60-70 mph the car will downshift when applying throttle.
I put the car into manual mode and shifted through the gears; I can engage all 5 gears but when 5th gear is engaged and I apply throttle the RPM does not go up and car barely accelerates.
Dropping into 4th gear and it runs fine.

This may be paranoia but I thought I smelled something strange when I was in stop and go traffic and when placing my hand over the gearbox inside the cabin I feel that it is a little warm.

I am struggling to research this, I read some threads here and on reddit I believe that suggest it may be one of the solenoids.

Any help or suggestions would be greatly appreciated.

 

What you described sounds normal. 5th gear is for cruising, not accelerating. The car should downshift to 4th or even 3rd gear when you attempt to accelerate.

The transmission is under the hood on the driver side between the 2 front wheels. Its extremely unlikely you can feel heat in the cabin from the transmission.

 

Any luck diagnosing the issue krastem? I appear to have a similar issue in 5th gear. Car will briefly jolt/shake and lose acceleration in 5th gear under medium load, rpm will bounce up/down half a tick.