Hello all. I recently purchased an xj6 1995 4.0 109k miles. I’ve had it for around 2 months with no issues. Recently, I’ve noticed that there has been some random shaking around mph. It is there for a bit then fades and will come back again. Can anyone help?

 

Sorry around 30 mph*

 

One of the first things to do would be to have the tires checked over, there could be issues with balancing or abnormal wear.
Then look into the wheel bearings to see if anything is loose down under, bushings and shocks are worth checking.
Check all the fluids are where they are supposed to be and recently refreshed, oil and transmission fluid particularly.
Make sure the spark plugs and coils are in good shape with no oil in the wells.
Check everything in the engine bay looks like its connected to where it should be
If it's none of those, it could be time to get your hands dirty.