I’ve noticed in the past couple of days that when my Fusion is fully warmed up and stopped at a traffic light I’ll feel a short rocking forward-backward. Almost like a bunch of guys are pushing on the car from behind. Sometimes, if it is really bad, I’ll even seen the RPMs dip a little bit.
I was thinking that it might be motor mounts causing the sensation. But what would be making the engine dip idle RPM?
Additional info: 138k miles on it and transmission fluid was last changed at about 80k. Plugs changed at 100k. New air filter installed a couple weeks ago.