I have a 90 Lumina. My symptoms are rumbly driving all the time except when taking turns, steering wheel is off center to the right and go left when it is straight, when I hit a bump straight on and only straight on I get a one clunk sound ( doesn't sound like rubber or metal and only really happens on railroad tracks or big holes), I have heard a loud popping sound when driving out of the LF wheel well. Sounds like a soda bottle that had been squeezed popped back open, steering wheel pulls going over bumps or ice patches. I have had a couple of mechanics look at the struts and they are fine. The RF tire rod end and struts are new, the LF balljoint and struts are new. Sway bar bushings are new. The funny thing is I took it to my regular mechanic to diagnose and asked to have the front tires changed and rotated and the car did great til I made it to work and had to change the valve stem. The symptoms have gotten progressively worse since then. Car also has front end shake side to side (so it feels) when braking and the wobble and vibration is much worse going around 5 miles per hour. Not too bad when going 50 MPH.I plan to go this weekend to have the engine and tranny mount replaced just because of vibrations in the cabin and a clunk in reverse but was wondering if anyone had any ideas about the rest and how to go about checking for them. The jacking up the car and pulling doesn't show anything.