I don't think this is my imagination, but every once in a while when sitting at a stop light, I could swear I start getting a vibration through the brake peddle. It also seems the RPM's have gone down from their normal 700 to something like 600 (I think, it is so hard to see). It has happened with both the air on and off, so it is not just the air kicking on. The car doesn't stall, but it seems to idle rough until I get going again. Anyone else have this issue. 2011 FWD RDX with 45K miles. Thanks!

 

I have seen the same thing on my car. It's only a very slight vibration, not the same as the vibration from the extra load on the engine when the a/c is on. I imagine a lot of people get it as it's just the idle adjusting - you have to be a picky driver to pick up on these little things. I wouldn't give it much thought if the car isn't stuttering or stalling. You will start to notice more vibration over time as the engine mounts wear out, but at 45k you should be good. I'm at 95k and it's still pretty smooth, but I do think my shocks are starting to show their age.

 

I think you are correct TomTW. It is only slight sometimes, so not a big deal. Just strange that all of sudden I can feel it coming through the brake pedal. Didn't know if it was possibly some buildup on the throttle body, which I have had in other cars. Thanks!

 

Hey man. Could be several different things. Could be a vacuum leak or something else. Hard to tell without looking at the car.

 

Mine does it as well. I rarely let it idle so I haven't noticed it until recently. Until it gets worse or throws a code I'm not worried about it.