thats exactly what i figured last night, revving in neutral you could feel the resonance in the cooler with your hand on it, so today i went out and bought soft silicon 'hump' hoses to hopefully take up some of the vibration transferring through the intercooler pipes. If that doesnt fix it altogether, ill mount the cooler on rubber mounts.
does your 3T make a fair bit of top end (head) noise? not tapping or anything, just a very mechinical noise. mine has done it before and after rebuilding the head, maybe i'm just spoilt by other engines with cam belts instead of chains....