It's my wifes car so I don't know when this started. I drove it the other day and it sounded as if the dash was going to shake loose. The car vibrates badly at idle. It smooths out somewhat at higher rpms, but I can tell it's still there. I've replaced the motor mounts. The driver's side was definately bad. The other two were good(I know this after having replaced them). What else could it be? It used to get better as it warmed up but now it stays the same(per wife). I checked the plugs-all looked same(good color). No codes. Gets the same mpg as usual. I can feel it when I put my hand on the valve cover. It's not as smooth as it used to be. Could something be hitting the body/firewall/k-member somewhere? I can't figure it out
. 150000 miles. Timing belt replaced 20000 miles ago.