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Old 03-20-2013, 06:51 PM   #1
subey-noobie
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Default Fluttering noise during acceleration

I have an 07 WRX and I got this weird fluttering noise when I'm accelerating at low rpm's and I can't really come to an understanding as to what it is. I've heard other people with this same issue or something similar and I'm just seeing what other people can tell me here.

Basically, during initial acceleration I heard this flutter type noise but as I give it more throttle I hear less of it or none at all. From what I've read elsewhere it seems to me it might be a wastegate flutter where the wastegate is only partially open given light throttle, but as the throttle/wastegate opens up more the noise disappears. Assume that this is the issue, can this be fixed by simply replacing the wastegate with another one or an aftermarket blow-off valve? I've also heard that a blow-off valve might cause another problem for the vehicle which is why I'm a little hesitant to take that route so far.

If anyone can tell me anything about this problem I have with that noise and any known issues for replacing a stock wastegate with a blow-off valve, I'd appreciate any opinions or advice. Thanks in advance!
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Last edited by subey-noobie; 03-20-2013 at 06:59 PM. Reason: typo
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Old 03-20-2013, 07:11 PM   #2
zagarus
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What sort of modifications have you done to the car or is it still stock? On a lot of "tweaked" cars it could be the wastegate unable to keep up with the boost change as it tries to regulate and stabalize the boost as you described.

Either port the wastegate or get a bigger turbo with an external wastegate of your choice...You know you wanna
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Old 03-20-2013, 07:42 PM   #3
Cranker625
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blow-off valves can be very bad unless you know exactly what you're doing.

what other mods do you have? any electronic gauges in your cabin?
is it a flutter or a rattle? maybe it's your heat shields vibrating?
there could be all kinds of possibilities
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Old 03-20-2013, 07:44 PM   #4
Drakar
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Location: Coquitlam, BC, Canada
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Id get some data logging before jumping to any conclusions.
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Old 03-21-2013, 12:29 AM   #5
danny_d19
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Did it just start happening or has it been like this since you got the car? Sounds like it's probably the wastegate or maybe even a boost leak, but more likely the WG.
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Old 03-21-2013, 10:33 AM   #6
ShiftGear
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Im sure its your wastegate
I have to port mine too
I have the same problem
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Old 03-21-2013, 11:20 AM   #7
Blucid
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Its the same problem I have, its the wastegate not keeping up properly with the boost build up at the beginning.

I have COBB SF Air-Intake and when I put my foot down all the way, at the beginning in higher gears before I hit 3500RPM the flutter happens.

Nothing bad until you get a better wastegate or better tune, only thing I would watch out for is, you might throw a code. I did already twice. Only when I am cruising in 6th gear and I mash it on the hwy.

Code: P0244
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Old 03-21-2013, 04:39 PM   #8
subey-noobie
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I bought the car used about a year ago and noticed the noise after a month. The only mods I think could possibly affect this is my aftermarket exhaust, I heard getting one would make the noise a little more noticeable than a stock one. I've also got COBB stage 1 so this might've affected it as well.

I read somewhere that it could also be the heat shield rattling but it doesn't really sound like a rattle to me but I'll try to listen for that. Assuming the noise is from the wastegate, does anyone know if this could cause any issues with anything? I've driven the car for a year with this noise so anything could help!
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Old 03-21-2013, 07:18 PM   #9
2010 WRX Limited
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I don't think what you are describing is a problem. It's most likely wastegate flutter and it's normal. It does get louder when exhaust and DP are changed. Not to be confused with boost creep which only happens when you go WOT for a long time. You have an 07 WRX and the turbo is not the same as these guys who are getting boost creep on the 08+ WRXes and STIs... You could have creep too but it doesn't make that sound, just crazy power .
Now there's one more sound that's a little like wastegate flutter but different, it's cavitation or compressor surge. It happens to me if I go WOT really quick in say 4th gear around 2700 RPMs... I suggest you try some logging with an accesport or Tactrix to see what's happening before porting wastegates or anything.
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Old 03-22-2013, 12:49 AM   #10
subey-noobie
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Quote:
Originally Posted by 2010 WRX Limited View Post
I don't think what you are describing is a problem. It's most likely wastegate flutter and it's normal. It does get louder when exhaust and DP are changed. Not to be confused with boost creep which only happens when you go WOT for a long time. You have an 07 WRX and the turbo is not the same as these guys who are getting boost creep on the 08+ WRXes and STIs... You could have creep too but it doesn't make that sound, just crazy power .
Now there's one more sound that's a little like wastegate flutter but different, it's cavitation or compressor surge. It happens to me if I go WOT really quick in say 4th gear around 2700 RPMs... I suggest you try some logging with an accesport or Tactrix to see what's happening before porting wastegates or anything.
I'm not too sure what you mean by "creep" but yeah I'm 90% sure its not compressor surge either. Mainly cuz from what I hear, compressor surge only happens if the fluttering noise is happening as you decelerate. When I go WOT the noise disappears pretty much, tried it out after one of my mechanics told me about the wastegate flutter. But yeah, maybe I'll whip out the access port and see what I can find. Thanks for all the input guys!
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Old 08-12-2017, 12:04 AM   #11
Mndsnts86
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Default What data logs

Quote:
Originally Posted by 2010 WRX Limited View Post
I don't think what you are describing is a problem. It's most likely wastegate flutter and it's normal. It does get louder when exhaust and DP are changed. Not to be confused with boost creep which only happens when you go WOT for a long time. You have an 07 WRX and the turbo is not the same as these guys who are getting boost creep on the 08+ WRXes and STIs... You could have creep too but it doesn't make that sound, just crazy power .
Now there's one more sound that's a little like wastegate flutter but different, it's cavitation or compressor surge. It happens to me if I go WOT really quick in say 4th gear around 2700 RPMs... I suggest you try some logging with an accesport or Tactrix to see what's happening before porting wastegates or anything.

What data logs would you be looking at? Having the same flutter noise on WOT as well boots gauge will bounce?
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