Banging coming from under dash board.

[SiriusFan]

Very odd issue.

We have a 2010 Expedition. It has almost 70k on it but overall it runs and drives great.

The other night I went out to the store and made a couple stops after that.

When I left the store there was a loud banging coming from the lower part of the dash in the center. Then it stopped. Maybe 4-5 bangs total. Scared me for a minute as I had never heard it before in the 5 years of owning it.

Went to the next store and when I started the engine and did it again.

Made a stop for 5 minutes but didn't turn the engine off. It didn't happen then.

Got to a stop light turned engine off and turned it on again and the banging started.

And the bangs aren't random either. Almost perfectly spaced out between each bang.

It doesn't last long but it seems to happen anytime the truck is started.


My guess is that maybe just maybe it has something to do with the cd/dvd changer in the dash although the banging is coming from a good distance below it.

From what I remember there is a DVD and a music CD in there but I can not eject them as the system says that there are no discs. Pretty sure that there are.


So what should I look for first.

Thanks

 

[montecarlo31]

I would take out any DVDs incase you believe it to be that. I would also turn off all the climate controls and see if that fixes it. It very well maybe the plenum door having problems opening and closing or getting stuck. Can you change from defrost to feet to vents without issue?

 

[01yellerCobra]

I wonder if you're hearing the starter hitting the flywheel and it's reverberating through the trans tunnel? The gear may not be retracting completely when the key is released.

 

[Mediamonkey11]

Blend door!

http://www.youtube.com/watch?v=BFA57sTEtLU

 

[SiriusFan]

NICE. Thank you.

It sure sounds like the blend door.

We have the electronic switches (if that is the correct term) so no dials like the ones shown in the beginning of the video.

Didn't have time to finish watching the whole video yet but that is definitely the sound.

I believe the banging came on in the middle of a longer ride also so the starter was probably not the issue. Although I just had the right exhaust manifold replaced and my mechanic is awesome so even it was the starter is might not have been a big deal to replace.

Thanks will report later.

 

[SiriusFan]

NICE. Thank you.

It sure sounds like the blend door.

We have the electronic switches (if that is the correct term) so no dials like the ones shown in the beginning of the video.

Didn't have time to finish watching the whole video yet but that is definitely the sound.

I believe the banging came on in the middle of a longer ride also so the starter was probably not the issue. Although I just had the right exhaust manifold replaced and my mechanic is awesome so even it was the starter is might not have been a big deal to replace.

Thanks will report later.

Done. It happened to be both motors. Driver and Passenger side. My mechanic said the the drivers one is a real PIA to get to as the dash needs to be removed more so when replacing the drivers side.

All is good now, except the power running boards but that is for a different thread.