I am trying to troubleshoot my 2000 Grandprix, have replaced CV joint and hubs, powersteering pump, and several vaccum hoses, nothing has helped at all.
Symptoms: upon acceleration at any speed over 30 mph, the car begins shaking, the longer I drive it the worse the shaking gets. It feels like an old Motel bed you use to but a quarter in for a massage, just shakes the heck out of you. the engine smooths out going downhill or not accelerating. Going uphill the engine feels like it cannot breath and the shaking is really hard. It smooths out a bit if no acceleration is taking place and I am able to maintain about 70 mph on the hwy, but does not go away completely. Any ideas on what to look for next, at the end of my rope here.