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Discussion Starter · #1 ·
Hello,

Just purchased a 2008 ISF used with 20k miles. I noticed that when turning off the engine, there is a noticeable "clunk" noise coming straight from the air intake area in the engine bay.

The clunk appears to be from the secondary air intake baffle that "opens" after the engine is turned off. I figure this is the vacuum controlled secondary baffle that opens up at 3600-3800 rpms+.

Just wondering if everyone with an ISF hears the same "clunk" due to the baffle actually "opening" when turning off the engine.

Took a video
. Sorry, didn't have a camera man to hold the camera steady.

Thanks for anyone's input
 

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Just curious, do you have the engine covers off on purpose to demonstrate the clunk?
 

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Discussion Starter · #3 ·
Yes, I removed the engine cover to demonstrate where the clunk is coming from. With the engine cover on, you can't really see the baffle "open" when the engine shuts off.

Just curious, can anyone check to see if the baffle is in the "open" position when the engine is off? I don't see why the baffle would need to be in the "open" position, only to close itself upon engine start. Thanks

Just curious, do you have the engine covers off on purpose to demonstrate the clunk?
 

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when the engine is started, the vacuum closes the secondary intake so it runs quieter, once the engine hits higher speeds, the vacuum is bypassed and the secondary opens. resulting in the loud "bark" at 3600rpm. so the default position of the flap is open when the car is off. and it closes when it is at idle, and under 3600rpm.
 

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when the engine is started, the vacuum closes the secondary intake so it runs quieter, once the engine hits higher speeds, the vacuum is bypassed and the secondary opens. resulting in the loud "bark" at 3600rpm. so the default position of the flap is open when the car is off. and it closes when it is at idle, and under 3600rpm.
i verified this last night
the flap is normally open when the car is off...
 
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