Volvo: 2000 volvo s40 vibration, 2000 volvo s40, sterring wheel

Question
Hi I have a 2000 volvo s40 1.9 turbo it has 75,000 miles on it. My question is that my car begins to vibrate when i reach 45-65mph. When i accelerate I can fell the sterring wheel shake and it fells like my tires are bouncing up and down. As soon as I let go of the gas,the car runs smoothly as though nothing is wrong. I thought it might be the tires needed balancing, but I had the tires rotated and balanced and the problem persists. I am going to take it to the dealership but I wanted to have an idea of what might be the prob b4 I take it and can you give me an idea of price range i might b looking at? thank you  

Answer
Hello Anthony! It is very tough to give you a specific diagnosis without driving the car. If the tires and wheels are ok, I would have them check the suspension, engine mounts and crank pulley. Prices will be different from shop to shop. If you let me know what they tell you, I can let you know if it is a fair price.

Jimmy