vacuum air noise in cab

[paulrc35]

New to this forum looking for help my bride of 20 years has a 2008 be and there is a vacuum air noise in the cab on the pass side. Was looking for some ideas on what the issue is.

Thanks
Paul

 

[Rcflyer330]

I am betting its the vaccum canister check valve in the engine bay. They are a common falure actually I need to replace mine again. There are many threads on this exact problem. I will get pictures of the location. They are about $15 from the dealer and very easy to replace.

 

[Flag Gibby]

I doubt that he would be able to hear the check valve from inside the vehicle on the passenger side. There are several vacuum lines that activate doors on the HVAC system, it is possible that a line on the vacuum reservoir came off (behind the glove compartment) and that is what he is hearing. Paulrc35, is the HVAC system working properly when you switch between the different modes and do you still hear the noise if you turn the HVAC system completely off?

 

[dantheman68]

Is the sound constant or occasional?

 

[Rcflyer330]

Check out this forum
https://www.explorerforum.com/forums/showthread.php?t=322766


Also v8 or v6?

 

[Flag Gibby]

Thanks Rcflyer, I had forgotten that when the HVAC system is on you can hear something in the system hissing in the cabin on the passenger side when the check valve under the hood is acting up.

 

[fordbluefamily]

Another vote for check valve under the hood. I am on my fourth one. They are junk quality. It hisses loud on the passengers footwell when they go bad HVAC on or off. There is a vac canister there that empties and fills as you step on or let off the gas.

 

[snakester]

Fixed this with a new vacuum check valve. No guesswork.

Purchased for $10 here : http://www.rockauto.com/catalog/moreinfo.php?pk=380402&jnid=2&jpid=0

It is located here:

Just pull it apart and replace it with the new one installed in the same direction and its done. 5 minutes including the test drive.