Knocking noise in the Dash

[Ron from Tucson]

Hi, My indicator display came on telling me I needed to change the oil soon.
I noticed a "knocking" sound when I started the truck. When I get to my destination, I had the oil changed, and the display was reset. But, the knocking noise still presists, so I guess it's not part of the alert. Anyone have a clue what this obnoxious noise is? Thanks.

[Mr Mac]

Is the noise you hear coming from the engine or somewhere else?

[Ron from Tucson]

The noise sounds like its near the radio/cd player. so I played different cds, so its not that.
I was wondering it if had anything to do with the maintenance reminder, for the oil change.
When that came up, is when the noise started, upon turning the key and starting the truck.

[Drangd]

adjust your temp knob. Mine started doing the same thing some months ago.
I adjusted the knob off of the coldest setting and the noise stopped. Was not an issue until I got back to Tucson and its triple digits now, Pretty sure it is a air flow flapper to coin my own words for the parts. Have not had the inclination to start taking the dash apart to get to the problem. It is not that hot yet.

[Ron from Tucson]

Thanks Drangd, I'll give that a try. The problem noise is so sporadic, that it is hard to pin down. When I mentioned it to a Ford service tech, he looked at me like I was speaking a foreign language.

[Drangd]

Mine started out once in a great while a well. Now it is pretty constant if I allow the temp know to go max cool. Nothing to do with the push buttons just the knob.
Let us know if this suggestion helps.

[Ron from Tucson]

Thanks I will, when it warms up a little, in Illinois.