CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Blend door issue

My vehicle is a 2007 Chevrolet impala 3.5L. My passenger side side blows cold air when I have the heat on while the driver side works properly. I know this is a blend door issue but I am not sure exactly what the problem is. The common issue with this car is that the actuators become faulty when the plastic cogs in the actuators strip and it causes a clocking noise. I have had this issue in the past with both of the passenger side blend door actuators and changed them both out. There is no clicking so this does not seem to be a repeat of that issue. Please help me understand what the problem is.

You seem to already understand the issue quite well. You are correct about the blend door actuators chewing up their plastic gears and needing replaced. That is a common failure. Sometimes the door is obstructed and the actuator just destroys itself trying to operate normally and the door movement is the issue. Other times the controller of the actuator is the problem…not telling the actuator to function. You need to try and determine which failure mode you have.

Remove your actuator and see if you are able to manipulate the door with your hand…how does it feel? Leave the actuator unhooked from the blend door and command it to move…does it move? Its good to have a known good or new actuator at this moment so you can then try to operate the new one with the dash controls… This will help you determine if its the actuator, the door, or the controls of the car… The controls (electronic) are another common culprit and just fail in a way that it doesn’t properly operate the actuator… So you need to try to run tests like I’ve outlined to get to root cause. There could be a fuse involved as well so look at your fuse diagram and see if any are related to this as a matter of course…

1 Like