Thanks for your opinions.

gmercoleza: No. The noise occurs when standing still.

dpetryk: Very interesting and original idea, but the vacuum parts are too far from the noise source...

What if the noise is a kind of rattle then what would it be? I checked the charcoal canister and the plastic protective cover under the engine, but they are solid.

The drag link ball joints are not in good condition. I can move the drag link without big efforts. The other joints are fine.

Any helps? The noise makes me #$%^&*