Totally Stumped (Deep Rumble) 2002 SE

Hello All,

I have a 2002 Ford Focus SE that has a deep rumble during low speed (under 50MPH) acceleration and when hitting bumps on the road at low speed. There is no engine light. There are no codes. The car gets good MPG about 27, and has good power. I have taken it to my mechanic twice and to another one and all of them cannot find the source of the problem. My mechanic said he thought it was brake vibration. So this is everything I had done to the car.

1. Change Oil
2. Change Transmission Fluid / Filter
3. Change Plugs, and Wires
4. Change Front Rotors and Brakes
5. Change Drums and Pads
6. Change all 4 Struts
7. Change the Battery
8. Change the Alternator
9. Change the Belt
10. Change the Brake Fluid.
11. Change Fuel Filter
12. Change Tires

I'm at my wits end. The car performs like it was new but the noise won't go away.

Thanks

Bluelogic

I forgot to mention it only happens when it is cold. After driving awhile it goes away.

Thanks
Bluelogic