Hello I'm new to the forum today. i have a 02 XJ Sport with 83k miles and I'm having a problem with it. about a month or so ago i started getting a rough idle. well now when I'm on the expressway and i try to accelerate i get alot of vibrations into the cabin almost like I'm going over a badly paved road. it wont vibrate if i kick the trans down into passing gear, but only when i speed up and stay in the same gear.

before you ask i still have the original timing chain and tensioners but the car exhibits no rattles at start up, but i do have the rough idle.

i changed the spark plugs even they looked fine just incase. it made no change.

any suggestions?

Thanks,
Devon