Strange hammering sound after car is parked

[Sally M]

Sorry... I am new to the forum and think I posted this in the wrong area a little while ago so will put it here which may more likely be where it belongs...
I have noticed, should I happen to be near the car a short while after I've parked it that there is a sound like someone is hammering something under the hood. Lasts maybe 8-10 "hits" then stops. Any idea what could be causing this? Thank you!

 

[WannabeST]

Sorry... I am new to the forum and think I posted this in the wrong area a little while ago so will put it here which may more likely be where it belongs...
I have noticed, should I happen to be near the car a short while after I've parked it that there is a sound like someone is hammering something under the hood. Lasts maybe 8-10 "hits" then stops. Any idea what could be causing this? Thank you!

When you say there is a hammering sound, is it loud? or does it just sound like taps.

And also is a short while like a few seconds after parking or a few minutes?

 

[isis]

It’s the blend door behind the glovebox. It’s toast.

 

[Sally M]

When you say there is a hammering sound, is it loud? or does it just sound like taps.

And also is a short while like a few seconds after parking or a few minutes?

It has varied quite a bit... but never less than 5-10 minutes and sometimes longer....

 

[Sally M]

When you say there is a hammering sound, is it loud? or does it just sound like taps.

And also is a short while like a few seconds after parking or a few minutes?

Forgot to say that it is fairly loud.

 

[Sally M]

It’s the blend door behind the glovebox. It’s toast.

I'll tell the service dept that in the morning.... I have no idea what that means but hope that they will.

 

[Capri to ST]

It’s the blend door behind the glovebox. It’s toast.

That was my first thought also.

 

[Capri to ST]

I'll tell the service dept that in the morning.... I have no idea what that means but hope that they will.

Our HVAC system has three actuators, little motors that move around different parts of the system when you make adjustments or after you shut the car off. One controls the temperature, one controls where the air goes, and one controls whether air is fresh or recirculated. That last one is the one behind the glove box which seems to be the one you're hearing.
They have these cheap plastic gears in them which can strip out over time, and when they do the actuator keeps trying to move them but since the gears are stripped out that doesn't happen, and the whacking sound you hear is the motor turning something trying to function. This is a known issue in our cars and in many other modern cars.The one behind my glove box is also making noise and I'm getting ready to replace it. It's annoying, but not a huge deal otherwise.
Here's a thread discussing it which probably has a lot more information than you need, but I will link it here in case you find it helpful-
https://www.fiestastforum.com/threa...cking-sound-part-numbers-video-install.22458/