Flutter sound under heavy acceleration.

Jan 30, 2012 | 11:56 PM

dgkalis

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g55

Flutter sound under heavy acceleration.

Any one ever get a flutter sound that seems to be coming from inside the big center vent on the dash under wide open throttle.

Its starts making the flutter sound higher up the revs.

If i let off... then blip the throttle... it will flutter until the revs come back down. I can then squeeze the throttle with out the flutter or even blip it with no flutter as long as im below 4-4500 rpm

There is no flutter under say... 4-4500 rpm. It could be something in the engine bay.. but really sounds like its coming from behind the top center of the dash... inside that big vent or whatever is under what looks to be a big vent.

Hoping someones heard of this before i need to start digging.

thanks.

Jan 31, 2012 | 02:12 AM

AWOL

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e55

record it on video

Jan 31, 2012 | 02:30 AM

dgkalis

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g55

Quote:

Originally Posted by AWOL

record it on video

i will do that tomorrow!!

Jan 31, 2012 | 03:34 AM

BBBSS

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From: Chicago

03 E55 AMG, 06 Harley Road King Custom 06 Ram 2500 Cummins, 97 Firebird Race Car, 88 Cutlass Supreme

Try changing your heat to blow from a different area or turn it off completely and see if that changes anything.

Anyone know if these controls are vacuum or electric motors moving the flaps in there? If its vacuum perhaps there's a bad check valve allowing boost into the vacuum controls for the HVAC system?

Feb 1, 2012 | 02:07 AM

dgkalis

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g55

Here are the video's of the sound.
First heat was on... second heat off. It made no difference.

There wasn't enough room to stay in it... but you can really hear it.

Best guess??

http://www.youtube.com/watch?v=KYBVI...e_gdata_player

http://www.youtube.com/watch?v=iaEvn...e_gdata_player

Feb 1, 2012 | 05:09 AM

BBBSS

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From: Chicago

03 E55 AMG, 06 Harley Road King Custom 06 Ram 2500 Cummins, 97 Firebird Race Car, 88 Cutlass Supreme

Hard to tell whats going on there. Any chance its an exhaust leak only showing under a load? Motor mounts in good shape? Motors not twisting a lot and causing something to move and leak?

Kinda just taking stabs at it here.

Feb 1, 2012 | 05:47 AM

dgkalis

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g55

Quote:

Originally Posted by BBBSS

I will check all of the above tomorrow.

Thanks...

I really have no clue what it could be. It is hard to get the sound to translate with the video.... It only happens at that high rpm. If i keep the revs that high.. it will make the vibration sound every time i peddle the throttle. But its sounds smooth as soon as the revs drop a bit lower.

Maybe i'll get a passenger to try and stick their head up there while flooring it. Problem is... tires want to spin at a low mph.. and its sketchy to hold the speed and such high rpm... on the freeway. Too bad i can't free rev it up and see if the sound is present.

Is there a way to bypass the free rev limiter?