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Weird blow-off behavior with Procharged V6

2133 Views 13 Replies 4 Participants Last post by  bluebyu12
Procharged 2011 V6 here. Typical setup, but with the excess boost dumped to the atmosphere. Noticed last week an odd sound coming off of boost. Popped the hood open to investigate more, and instead of coming off of boost, and hearing the typical “hiss” down, it’s a pretty violent flutter/vibration, almost as if it is trying to force excess boost back out through the original intake. Took off the filter at the end of the dump hose (speculating it might have clogged enough to cause an issue), but that didn’t change anything. The vaccum hose connecting and controlling the valve is working, as the actuator moves like it should during idle, acceleration, and off. Even pulled the valve off to make sure the internals were fine. I’m stumped. Any thoughts?

I have videos, but just wanted to put this out there first. I’ll try to get them posted asap.
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is there any debris caught in the valve not allowing it to fully open. that or sounds like a vacuum leak or issue, mines operating fine. this just came about out of no where?
Okay. Here are some videos and pics. Disregard the "Airaid" logo'd prefilter on the intake filter. It's just a standard K&N.

Photo of valve closed
http://i1102.photobucket.com/albums/g442/sketchy00/Procharger2/scbypass-closed.jpg

Photo of valve opened
http://i1102.photobucket.com/albums/g442/sketchy00/Procharger2/scbypass-open.jpg

Observations of flutter/vibration
Procharger2 :: scvid3.mp4 video by sketchy00 - Photobucket

Action of valve while off
Procharger2 :: scvid2.mp4 video by sketchy00 - Photobucket

Action of valve while running, plus more vibration/flutter
Procharger2 :: SCvid1.mp4 video by sketchy00 - Photobucket
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Update. ATI suspects it might be a bad blow off valve. They are sending me out another one under warranty. I'll throw it on when I get it to see if it fixes the matter.
Yeah man something seriously wrong with that. I'm sure the new one will fix it right up
Yeah man something seriously wrong with that. I'm sure the new one will fix it right up
Yeah, the familiar blow-off hiss mysteriously dissappeared one day. I have a small K&N filter at the end of the dump tube, and thought that clogged or something. Definately not the case. I'll keep you posted.
Action of valve while running, plus more vibration/flutter
Procharger2 :: SCvid1.mp4 video by sketchy00 - Photobucket
The valve seems to be working (mechanically) in relation to the engine rpm / vacuum from what I can tell on the video. There is a possibility that the adjustment on the valve has changed (from vibration?) causing the plate/blade to over-travel and is blocking the air as if it was shut.
The valve seems to be working (mechanically) in relation to the engine rpm / vacuum from what I can tell on the video. There is a possibility that the adjustment on the valve has changed (from vibration?) causing the plate/blade to over-travel and is blocking the air as if it was shut.
That is a good question. I looked to see if there was anything obvious like that, and it didn't seem to be the case. The vacuum is definately there as well. I was scratching my head as I was watching it happen, as it just didn't seem to make sense. I have my suspicions that the blow-off valve is not the problem, but it is the first thing that ATI suggested to address.
That is a good question. I looked to see if there was anything obvious like that, and it didn't seem to be the case. The vacuum is definately there as well. I was scratching my head as I was watching it happen, as it just didn't seem to make sense. I have my suspicions that the blow-off valve is not the problem, but it is the first thing that ATI suggested to address.
Disconnect the vacuum line, ziptie the lever on the valve so that it is open all the time and see if it still happens. The valve not working properly is the only thing that would cause a flutter like you're experiencing. What's weird is that it worked fine and somehow now it doesn't even though it is mechanically moving.
Disconnect the vacuum line, ziptie the lever on the valve so that it is open all the time and see if it still happens. The valve not working properly is the only thing that would cause a flutter like you're experiencing. What's weird is that it worked fine and somehow now it doesn't even though it is mechanically moving.
Great idea. ...Will do.
Any resolution?

I like Hector's idea of holding it open. The rubber diaphragm inside the BOV is known to leak. when you had it off did you open the door and then put your finger down on the vacuum line. It should hold the door open. If the door closes then you know the diaphragm is leaking.
I like Hector's idea of holding it open. The rubber diaphragm inside the BOV is known to leak. when you had it off did you open the door and then put your finger down on the vacuum line. It should hold the door open. If the door closes then you know the diaphragm is leaking.
Well, a replacement blow-off valve did the trick (covered under warranty). Upon closer inspection, it simply wasn't traveling to a fully open state, even though the screw/adjustment was properly set.
glad your problem was resolved. :bigthumbsup
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