I researched the source of a 500 Hz vibration at idle, mostly in the cab and I think I've located it as being the exhaust resonator touching the frame. The questions are: 1. Will replacing the struts increase the clearance between the resonator and frame. 2. Do the helical springs loose their springiness and collapse, making the repair above ineffective. 3. How do I tell if struts are "leaking" – everything looks pretty oily Notes: 1. I replaced the front motor mount which was chewed up. 2. The other two motor mounts appear intact. 3. Engine size = 2.6L Thanks for your help.
Are you refering to the catylitic convertor hitting the k frame on accel? Causing this noise? And does it not do it in reverse?
clean up the struts. Drive around for a while. Then check the strut again. If it is oil, it is probably leaking.