97 V8 SHO engine-to-body resonating/vibration

[Debo250]

I can both hear and feel a resonating beginning around 60 - 65 mph and goes away @ speeds above 70. Primarily felt in front passenger floor near firewall. Had cupped tires trued and balanced but didn't go away. Shop said rear motor mt broken and replaced (Ford said OEM part discontinued) with aftermarket - still didn't go away. Mechanic said "live with it" but it's too annoying in an otherwise perfect running car. Any ideas?

 

[stephen newberg]

You might check the subframe bushings.

pax, smn

 

[Mr Anonymous]

Also could be a CV joint or wheel bearing, but even a perfectly balanced tire that's cupped will still not ride right (something like a torn belt in the tire could also have caused the cupping and contribute to vibration).

Have you tried rotating tires?

 

[JrodSVT]

although it was probably a severe case but I had a factory Conti break a belt and it had vibration at all speeds. I would look at a CV joint or wheel bearing.

If a mechanic told you to live with it then he is not a mechanic but a parts changer. Everything can be fixed one way or another as long as the correct steps are taken to diagnose the problem. Try a new mechanic or another dealership.

 

[Debo250]

I'd love it if it were that. I'll check it out, thanks.

 

[Debo250]

Also could be a CV joint or wheel bearing, but even a perfectly balanced tire that's cupped will still not ride right (something like a torn belt in the tire could also have caused the cupping and contribute to vibration).

Have you tried rotating tires?

Duly noted. Thanks for your reply.

 

[Debo250]

although it was probably a severe case but I had a factory Conti break a belt and it had vibration at all speeds. I would look at a CV joint or wheel bearing.

If a mechanic told you to live with it then he is not a mechanic but a parts changer. Everything can be fixed one way or another as long as the correct steps are taken to diagnose the problem. Try a new mechanic or another dealership.

Couldn't agree more that anything can be fixed with the right investigation being conducted. I'll make my case and try another shop if necessary. Thanks!

 

[Red Devil]

Also could be a CV joint or wheel bearing, but even a perfectly balanced tire that's cupped will still not ride right (something like a torn belt in the tire could also have caused the cupping and contribute to vibration).

Have you tried rotating tires?

I'd look to the tires first, including the pressures you're running.