Well if the mechanic can't pinpoint the problem take it to another. Or listen to Hercman & the others & do the mounts, they must need changing at this point any how & if you are willing to do it Yourself, it shouldn't be that expensive. See labor is what makes most repair expensive.

But if the problem persist...you can buy the parts & get some tips from the guys here & do the next possible reason for the problem too...& you will have saved $$$ again.

If I were You I would rule out the problem by doing the cheapest 1st...they still needs to be done sometime shortly. And replacing "Worn Parts" can't be a waste of $$$...Trust me, You will Love that Smooth Ride & the feelings of Accomplishment...knowing that you did it All!

Well here's an easy way to check your lower motor mounts,undo the upper mounts you'll need a person to help then start your car apply brakes put the car in gear an rev to about 2000 rpm,the lower mount should hold the engine pretty level if its shot you will see the engine rise up quite a bit.Chico(pops)