it is a v6 auto. it is fine in park, but when in drive/reverse it makes a clicking noise from the belt side not the tranny side. It sounds like it is coming from the p/s pump right between the two cams. it also does this with the interior blower motor on and the a/c on but it isnt as loud. what could this be?

 

If when it's shifting gears it's the solenoid pac doing it's job ...
Also it can be the Evap canister solenoid doing it's job ... can't tell exactly