I repaired my friend's 04 inlet manifold chamber this weekend. It was making the typical noise from the power valves, with codes indicating the VIS motors were dead or stuck as well. The cover on the bottom is cemented in place, but you can remove it by applying a bit of heat with a small torch or heat gun to the edges where it bolts together. Apparently the factory uses the screws to squeeze the panel on after applying the cement.

Once apart, you can clean out the gunk and see how the power valves are linked together by a series of ball and socket connectors that attach to a longer arm which runs over to the VIS motor. The water/oil gunk mixture in the chamber seems to be the abrasive which wears out the ball joint, something like a hip replacement problem.

I repaired the sockets by heating slightly and squeezing them closed. When finished they snapped over the ball ends firmly. I lubed them up with a bit of moly assembly lube prior to final assembly, then put the cover back on with some silicone gasket maker after I cleaned up and sanded the mating surfaces smooth.

The balance valve was sticking as well, but you can pull the entire flap assembly out of the chamber by removing the motor and grabbing it with I pliers. It was sticking closed, so I removed a bit of material on the edges of the flapper with a file until it could swing shut without rubbing. total time for the entire repair, including reassembly, was about 3 hours.

I think there is still a problem with the throttle valve electrical connections as the idle is a bit rough until you put it in gear, and the accelerator pedal has an initial flat spot. Other than that, the chamber clacking is gone, and the engine is much quieter. At the end of the day it might be less expensive to buy a new chamber that includes two new motors, but I had to give it a go just to see if it could be done.