I've got a great running 08 T&C with a really clean interior. We really like our van. But it does have some issues. Currently, I'd like to fix the issue with the crazy knocking and buzzing noise it makes when the heater is on, or sometimes even off, and sometimes even when the van is completely shut off - it just keeps on banging and whirring. I'm going to dig into it real soon but thought I'd throw this out there in case anyone's dealt with it.

 

likely a blend air motor or modode door motor look under the dash driver and pass side when you hear it you can feel the motors making noise

 

Thank you CT. I think I found a possible culprit; the accuator. I pulled it and opened it up, and some of the gear teeth were broken off.

 

UPDATE: I installed the actuator on the driver's side (I assume there is one on the passenger side, too). The actuator adjusts the vent openings to get the right temperature mix to the cabin. A "simple" fix and the previous owner had actually left one with the van when we bought it. I say a "simple" fix because it's two screws out, remove and replace, and two screws in. But my back is still aching from twisting and turning to get under the dash to reach up to where the actuator sits and get a little socket with a little star bit on the screws. ADVICE: If you have to do this, be sure to have a magnetic reacher because the screws might drop down into the vent area, like mine did, but I got them out with the magnet. Also, if you don't have a magnet socket wrench, put a tissue inside your socket to hold your star bit - you don't want to get all twisted up under there and then lose the bit.