This is kinda random but how would I know if I have a broken or messed up engine mount?

 

you can see the mounts.

 

Ya but like when I start it there is like a vibration, it is kinda like a grinding type vibration but is happening in all gears including park

 

The passenger side mount is the one known to fail in most all high mileage xjs. Just get under it and look at it, and take a wrench to it to see if they are still tight. If the thing broke, your engine would sag, and would make terrible sounds. My dad had his break when he was going down the expressway last week, sheered the bolts right off. I threw mine up on the lift just Sunday to double check mine, cause it isn't uncommon for them to fail.

Edit: check your flexplate bolts, make sure they are tight. If they get loose, you get a nasty rattle. Mine were loose, and it was worse when i was idling, but could be heard all the time when driving. Just have to remove the inspection plate to get to them. I do not know the exact terms and way to go about tightening them, but a search will yield a writeup quick for ya.

 

Thanks fsher21 I will have to check this out

 

If I don't know where the flex plate bolts are how could I figure that out