Just turned over 80K- have been happy with this car-
Have this noise coming from the rear- could it be the shocks? have checked them and can't find anything loose?

 

It could be:

1. Bad rear struts.
2. Bad rear strut mounts.
3. Bad sway bar bushings.

A friend of mine bought the extended warranty for his XG and I think he had a problem with the strut mounts and got them replaced under warranty at about the same mileage.

 

on top of the rear struts there are insulator bushings, they go bad and that's what you have to replace. the part is cheap.

 

There is a 17mm nut on top, once that is removed- is the insulator bushing accessible?

 

After bouncing the rear of the vehicle, I knew the shocks were okay.
Jacked up the rear and removed wheels, could notsee that any bushings on any of the linkage were bad.
After replacing the wheel's & lowering the vehicle, placed a mirrow where I could see the top of the shock- the insulation bushing were gone- 1/4" gap. Will order new ones.
Thanks for the advise- will let you know if this solves the problem- 95% sure it will.
Mike

 

I have the same problem on my 2001 XG350 with 90K miles. Appears that I need to replace the rear strut bushings.

Can you please provide instructions on how to DIY them. Do I need special tools?

Thanks for your help.