TSX 09

I have a manual 2009 TSX with 30,000 miles on it.


The last couple of weeks i have noticed that the RPM sort of bounces when I put in neutral after I come from a gear.


For example: I am in 5th gear at about 4,000 rpm and coming to a stop light. I would normally shift it to neutral, I would see the needle go down to 800rpm then bounces to 1000rpm then settles back to 800rpm and stays there.


Is this normal? Anyone else have this?
Or could this be the beggning of something that needs to be fixed now? What can the reason be?

ulrblitzer

<p>That's odd. Mine doesn't do that.</p><p>Is your car warmed up when it does this? Might be coming off high&nbsp;idle and trying to find itself.</p><p>Or bad fuel? Spark? Are you finding any performance loss or MPG loss from the norm? Does it feel like it's choking or stuttering?</p>

wpgacurafan

Normal.
Happens with any modern MT car.
When the engine speed is decreasing fuel delivery is almost stopped.
When the engine speed reaches the programmed idle speed fuel delivery is resumed. In neutral there is no load so the engine spins up a bit then settles back to idle speed.

ssjoeboe9

<p>Agree&nbsp;completely with @wpgacurafan.</p><p>There is constant feeback loop within the system that &quot;takes&quot; information then &quot;gives&quot; information back to the system. That's why there is a slight delay with things like this. You can see it in almost everything from throttle response, to tiptronic shifting.</p>

TSX 09

thanks guys... make me feel better

cu2wagon

Ancillary load on the engine can play a factor as well. AC is probably the biggest parasitic load that will cause the engine to vary RPM. But radio, or seat motors might cause a dip/rise as well to some extent.

Sounds fairly normal though.

TSX 09

Thanks. I just asked because I have a 98 528i and it doesn't do that. But it could be normal with newer cars like wpgacurafan said.