Theres a little man knocking in my dash!! What is this noise?

speedyt5 · Post by **speedyt5** » 10 Jun 2016, 13:41

So lately there has been this knocking coming from inside the dash. No, not the dash mounts, and no not the recirc motor. I took a video of it. It will go on for minutes and I can't figure out what the damn thing is! Any ideas!?? I have tried changing from recirc to outside, it still knocks. Tried turning the vents from upper to lower to defrost, still knocks, even with the AC off it knocks. Today I went to take the glove box out to look in there and of course it wasn't doing it! A little man perhaps?

video here… Sound up!
https://www.youtube.com/watch?v=vWRtWoY ... e=youtu.be

101 · Post by **101** » 10 Jun 2016, 18:32

Try turning the temperature dials on the electronic climate control unit all the way to hot (or cool).

On both of my P80's you can hear the little motors that control the amount of heat added to the air stream fluttering a bit when the temperature inside the car is equal to the temperature outside the car. If moving the temperature dials eliminates the noise, you've found your cause. Unfortunately, I don't have a cure.

PS78 · Post by **PS78** » 10 Jun 2016, 20:36

Jeez. Sounds like microwave popcorn. Jk. Does changing fan speed effect the sound at all? With the headphones on it sounds like a fan or impeller blade grazing something.

Post by **scot850** » 10 Jun 2016, 22:12

Are you sure it is coming from the dash and not being transferred from under the car (loose heatshield?) or from under the hood?

It sounds like something is loose and knocking. Does the sound vary with speed or road surface (like if the road is rough over smooth)?

Neil.

speedyt5 · Post by **speedyt5** » 11 Jun 2016, 16:50

101 wrote:Try turning the temperature dials on the electronic climate control unit all the way to hot (or cool).

On both of my P80's you can hear the little motors that control the amount of heat added to the air stream fluttering a bit when the temperature inside the car is equal to the temperature outside the car. If moving the temperature dials eliminates the noise, you've found your cause. Unfortunately, I don't have a cure.

It's the blend door motor behind the dash, you were correct! its just a black box behind the dash, take the glovebox out, then undo three screws and put a new (used one) in. No big deal! Thanks guys.

smspup987 · Post by **smspup987** » 25 Sep 2018, 17:49

Hi I had the same problem yesterday. I had this noise before when the AC gas was low/empty and the AC was on, however this time it just kept knocking!!! no matter what, and will only stop when the fan is on High.

Solution: I turned the AC and re-Circulate on/off at the same time during different knocking times, I got it right and the knocking became a softer clicking noise. I randomly timed the the on/off again and the noise disappeared. Somehow by turning the AC and recirculate on/off reset something.

The car is a 850se 1996, right hand drive.

No sure if it will knock again, but touch wood. Please post if you found this useful or have a better solution.

Thanks

smspup987 · Post by **smspup987** » 25 Sep 2018, 17:50

BTW the car is not ECC just MCC (no climate control)

Post by **Ozark Lee** » 25 Sep 2018, 19:52

That is correct. The MCC setup does have the electric recirculation damper, that is the only motorized control with the MCC system. Usually the motor and its gearcase is OK but the lever breaks.

...Lee