I recently purchased an '08 C70 with 1.6 K on the odometer. This is the first Volvo I have driven since the late 1950's. There have been a few issues but it is quite clean and in good condition. There was a shudder under acceleration so I replaced the motor mounts and drive axles, which were shot. The car still has a slight shudder under heavy acceleration even after I replaced the spark plugs. The ride is smooth until I hit a bump in road when it feels like I'm driving a buckboard. Are these things normal?

 

If you hit a bump and the ride goes wack, you either have worn shocks/struts or worn suspension bushings. Do a visual inspect to look for any signs of oil leaking out of the tops of the struts/shocks by the piston and look for play in the control arms, ball tie rods, and sway bar end links. Any noises like clunking etc?

 

There is no noise in the suspension. What I mean by a buck board ride is a very stiff suspension that hits bump hard without much give in the springs. When I give the usual test for shocks by pushing down at the front or rear of the car, there is very little movement in the suspension. There doesn't appear to be any leakage in the shocks and no play in an any of the other components. What could going on with the slight shudder under heavy acceleration?