TimL

I recently bought a 2006 Avalon XLS with 66,000 miles on it. Although I didn't notices this issue on the test drive, it is consistent in occurring every since I bought the car. I can back out my driveway which is somewhat long in distance, put the car in drive and as soon as I hit the gas pedal to accelerate, I hear a 4-6 thumps in the right rear of the car. At first I thought it was the fuel pump reacting to the demand for more gas when I step on the gas. But then I have put the car in drive and stepped on the brake and give it a little gas with no noise. Then I thought it might be the exhaust hitting something, but if that were the case, I would hear the sound as I take off from a stop. The noise only occurs on initial start up as I can drive to work and never hear it again, until I shut the car off and then get in it and go which will bring up the thumping sounds again. Any suggests as to what is going on?