# Knocking sound **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** noises, windstar, ford\ **Created:** [October 4, 2009, 7:35pm UTC](https://community.cartalk.com/t/knocking-sound/37587 "2009-10-04T19:35:51Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![bgbrawner](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@bgbrawner](https://community.cartalk.com/u/bgbrawner)\ **Post date:** [October 4, 2009, 7:35pm UTC](https://community.cartalk.com/t/knocking-sound/37587/1 "2009-10-04T19:35:51Z")
When I adjust my temp control to hot or cold, a steady knocking sound comes from the dash. It is not related to fan speed, and perhaps coincidentally, the knocking sound started at the same time I could no longer get warm air. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [October 4, 2009, 7:40pm UTC](https://community.cartalk.com/t/knocking-sound/37587/2 "2009-10-04T19:40:41Z")
The blend door motor probably has a stripped out socket for the blend door shaft as these are made from plastic. This allows the blend door open to a point and then the blend door shaft slips in the socket and the blend door slams shut making the knocking sound. Tester ---
**Author:** ![bgbrawner](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@bgbrawner](https://community.cartalk.com/u/bgbrawner)\ **Post date:** [October 4, 2009, 7:49pm UTC](https://community.cartalk.com/t/knocking-sound/37587/3 "2009-10-04T19:49:25Z")
OK. I have located the blend door motor previously(but did not know what to call it) and I saw the plastic shaft. What is my next step? Replacement? If so, is it something I can purchase and do myself? Or is there a way to repair without replacing it? Also, does the fact that the blend door motor is not functioning properly related getting to no heat? Thanks! ---
**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\ **Post date:** [October 4, 2009, 10:58pm UTC](https://community.cartalk.com/t/knocking-sound/37587/4 "2009-10-04T22:58:41Z")
Yea, replace it. If you are handy, you should be able to replace it with the new part in hand it should not be difficult once you get to it and it seems you have already done that I have located the blend door motor previously(but did not know what to call it) ---
**Author:** ![bgbrawner](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@bgbrawner](https://community.cartalk.com/u/bgbrawner)\ **Post date:** [October 4, 2009, 11:12pm UTC](https://community.cartalk.com/t/knocking-sound/37587/5 "2009-10-04T23:12:46Z")
Joseph, thanks! After my last reply I used a pair of pliers to adjust the plastic shaft into position for hot air only, since cold weather is here now until Spring. But I saw the part online and yeah, it should be an easy fix…when I do it this Spring. I really appreciate your input!