Just bought a new (to me) 98 S70 T5. Nice ride, about 135K on the car right now. Everything seems solid except a vibration I can feel/hear from under the front of the driver's side floorboard.

It is not a RPM-dependent vibration, but it does go away once the engine is under a throttle load. Its always there when sitting at idle, and sometimes when I'll be coasting or slowing down without braking. I'm convinced it's either a worn/broken motor mount, or a loose exhaust hanger.

I am new to Volvos so I didn't know if this was a common problem someone else might recognize right away. If it is a motor mount, how do-able is the job for a shadetree mechanic? I've got access to a garage with lift and all necessary tools.

Glad I found this forum, seems to be a pretty helpful group here.

 

The front engine mount is more like on the passenger side underneath the car,the one in the engine bay on top,it,s more like in the middle might be loose pop up the Hood and check that Bolt,mine became loose over the years at one time.
by the way what State r u located.

 

i have the same problem... it is only present at 1-2k rpm. volvo dealer replaced the exhaust hanger but the noise eventually came back. how many exhaust hangers are there and is it possible that one went bad right after another?

 

If memory serves me correctly, there are 4 mounts you can check. There's one on the subframe on the passengers side behind the tire, the subframe almost directly under the turbo has one too. Those mounts are hydraulic, you can check to see if they're leaking or cracked. The other two chachouu described in the above post.
The one I had the most trouble with was the hydraulic mount under the turbo. I was fortunate enough to replace it while I was doing the clutch and had the subframe loose already.