Shakes, twitches, wobbles, jolts, spasms, surges, ripples.
Its either timing or fuel intake problem.
If your tires are in good shape, it's probably just tire balance. Low speed wobbles and shakes are normally bad tires, tread separations, just FYI.
engine rubber mounts or timin out
Need more info like what is the vehicle doing when it shakes, is it idling in park, driving down the road, braking, driving at highway speeds, etc.
Have a wheel alignment done. They will check the front end at the same time. Also are your tires properly balanced and round?
Check your motor mounts.
sounds like you have a leaky intake manifold
if the steering wheel shakes there can be a problem with alignment. shaking when braking would probably be a brake problem. constant shaking i'd expect you should check the muffler If the front end of your car shakes when just driving normally, your front end probably needs re-aligning. If it shakes when you apply the brakes only, your brake rotors are probably warped and need re-surfaceing. Impossible to answer question, please be more specific. It shakes when... I feel it shake in the steering wheel when... I'm driving along and... etc. It depends on WHEN it shakes. Low speed driving: damaged tire, U-Joint, ignition misfire, burned valve, low engine RPM. Highway driving: loose steering, faulty ball joints, tire balance, bent wheel, tire damage. Engine idle: burned valve, ignition misfire, motor mounts, low engine RPM, dirty injectors, EGR valve... All of the above plus quite a few other possibilities.
sorry to hear your problem .. i had similar problems .. try changing your front stabilizer's bush or change the whole bar ..