What is this ?

[Len 911]

What is this and how to test it..I have a buzzing evey now and then I can hear from inside .It sounds like it is coming from the back corner when in the car..so I would like to test it and know what it does.

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img]http://forums.pelicanparts.com/uploads26/20201222_1216231608657627.jpg[/img]

[Len 911]

[darrin]

that's an ambient air valve -- there to pull warm air into the intake during cold weather starts and they squeak (or make moose-like noises) when they fail. Yours looks like the earlier part, that's NLA -- there are a fair # of posts about ambient air valves on the forum -- here's one Do I need an Ambient Air Valve? --

[Len 911]

Is there any way to test it ?

[darrin]

you can temporarily remove the ambient air valve and plug the vacuum line going from the ambient air valve to the back of the throttle body and see if the noise goes away. The noise I heard is caused by the diaphragm in the AAV failing.