Not sure if this is a problem or I am just too sensitive. My TSX is less than 1000 miles now and it is an AT.

The symptom is like this. Between 40 and 60 mph speed, I can feel the engine spins (or the transmission?) not very smoothly at around 2000rpm. If I keep accelarating, then it would disappear immediately. If I don't accelerate or brake, e.g., the car goes downhill, and it can keep around that rpm and that range of speed, then I feel the car is not very smooth. much more vibration than other rpm or speed.

Any comments?

 

If you are going downhill and brake a tad (i.e. remove the foot afterwards), the car will lower the gear to help you slow down. It's done on purpose.

If you then accelerate a tad (then remove the foot), it will raise the gear to stop inducing the drag of the engine. And the car will start to gain speed by the simple fact it's going down a hill.

Does that answer your question?

You can manipulate this effect by going into "sport shift" and choosing your own gears. I do this when going down steep hills with lots of turns, to prevent fading the brakes.

 

Is this before the car has warmed up? Some transmissions when the tranny fluid is cold, it's a lot thicker and less fluid.
Or does it do this when it's warmed up as well?

Also, keep in mind that the TSX's 5 speed auto will utilize engine braking by switching to a lower gear if it detects you are going downhill and you tap on the brakes.

 

Hi, Thanks for all your comments. Well, it doesn't only happen during going downhill. When I drive on local road, maitain a speed b/w 40 and 60 mph, I can always feel this when I don't hit the gas pedal. The engine will stick around 2000rpm and becomes noisier. 2000 rpm seems to be the spot.
Despite how long I drive, it is always there. But for other speed, like lower than 30mph, I don't observe this, if I don't accerlate, engine will do down to 800rpm very fast, pretty smooth.

I guess it is due to gear change, but isn't this too dramatic, I mean, not smooth at all? On my other car, a much cheaper Nissan, I don't have this sort of symptom.

Could it be because it is still new (3 weeks?)

Tonight I went out for a joy ride, go around 85 mph, between 60 and 85, very smooth.