Need help on 99 xj 4.0 sport

Hi finally I reg here lol but I was wondering anyone out there kno if ur motor mount is bad or broke will it make a hard clunk when start up I can feel it under my feet lil the the center ?

i suppose it might. if you notice any movement of the engine side to side in the engine bay when its revved, your mounts are probably toast. they might not look bad, doest mean they arent. i put brown dog mounts on my xj after cracking manifolds and was suprised how worn the stock mount were.

Open the hood, start the engine, put in first gear, hold brake and gradually press the throttle until the tires spin or the engine moves. Do the same in reverse. You'll know if the mount is broken by how much the engine moves. Usually it's the pass. side mount and it happens when in reverse, the engine will move dramatically. They will still move a bit even if in good shape but not a whole lot.

It helps to have someone else stand off to the side and watch but you can see it from the driver seat as well.