At the beginning of the summer I brought the truck in for service. 1st ,Clicking noise and 2nd, engine knocking. Upon picking up the vehicle I was told that they were unable to reproduce the problem. ( apparently that response must be in the Ford Manual for dealers, because that's the number one response.) In October I was on a trip and suddenly noticed that I was either freezing or sweating. I could not get anything in between from the heater. Brought it back to the service writer and a mechanic happened to be nearby. The truck was assigned to that mechanic who heard my complaint about the clicking noise and the temp problem and recalled a bulletin about the problem. That day a mode door actuator was replaced and the problems were solved. Since then I found this website and may have an idea about the engine knocking.

At first i only heard a clicking noise in the dash coming from behind the air/heater control area. If i would turn the temp control to full either hot or cold the clicking noise would stop. Now i still have the clicking sound, but i also have either very cold or very hot no matter what the control is on. I put the ford in for repair on 01/05/10. After 3 days i was told they could not duplicate the problem. Ok, now i have contacted Ford customer service Division, have a case# and will return the vehicle first thing Monday morning along with information i have found about bad blend door motors sent in by jt893. I sure hope this helps. Looking forward to a clickless ride.

have a clicking noise in dash, With heater on about 1/2 to 3/4, clicking noise starts and if turn temp down, keeps heating with high heat, With control turned all the up or down, clicking will stop.,

Update from Feb 22, 2010: back in repair shop today same problem clicking noise in dash and unable to regulate temp in vehicle. In shop at 7:00 am. Dealer called at 2:00 pm. Stated they replaced blend door motor. Only driven a few miles after picking up vehicle. No problem so far!

I noticed that with the temperature set in the middle range the truck would go from really hot to really cold. One day when sitting with no radio on I heard a clicking noise and a motor running in the dash behind the radio area. The noise would go away when the temp was put to full hot or full cold but in the middle would click and run. The blend door (door that flips back and forth in the air duct to make it hot or cold) drive motor was replaced under warranty, but would have cost $300 part and labor normally. Why do they build everything with cheap plastic parts? Now the tranny is doing weird things and the warranty is almost out. :(