fxtgilly Posted February 10, 2023 Share Posted February 10, 2023 Today I noticed that my 2011 GT which has the cobb stage 1 map on it is only boosting to 14-15psi, when the target is 16.9. WOT and revving way past peak boost rpms it never even got past 15.2. Also noticed a small whistle/hum coming from the passenger side near the firewall when the turbo spools up, could be a leak? what are the most common leaks for these? i’ve heard bad things about the oem BPV, mine has a lot of miles on it and i was planning on getting a new BOV anyway… any input would help a lot! Link to comment Share on other sites More sharing options...
DrD123 Posted February 10, 2023 Share Posted February 10, 2023 (edited) Could certainly be the bov (well, more of a diverter valve). If you are at elevation, you won't hit the sea level boost targets, either (so if you are in NM or CO, for example, and are at 5-6k feet above sea level, you will not hit the target. Edited February 10, 2023 by DrD123 Link to comment Share on other sites More sharing options...
fxtgilly Posted February 10, 2023 Author Share Posted February 10, 2023 23 minutes ago, DrD123 said: Could certainly be the bov (well, more of a diverter valve). If you are at elevation, you won't hit the sea level boost targets, either (so if you are in NM or CO, for example, and are at 5-6k feet above sea level, you will not hit the target. Im in MD, so don’t think it’s sea level lol, gonna take a look at the inlet as well because it seems like that sound is originating from a lower point than the diverter valve. I think it’s the stock inlet so with all its age it could have a leak somewhere. Link to comment Share on other sites More sharing options...
NVAKeith Posted February 13, 2023 Share Posted February 13, 2023 I’ve heard the TMIC coupler is susceptible to boost leaks. Here is a thread about the stock coupler: 1 Link to comment Share on other sites More sharing options...
fxtgilly Posted February 13, 2023 Author Share Posted February 13, 2023 46 minutes ago, NVAKeith said: I’ve heard the TMIC coupler is susceptible to boost leaks. Here is a thread about the stock coupler: Mine has been replaced pretty recently by a shop the previous owner took it to, so I'll check but my new BOV comes in today so hopefully that fixes it. 1 Link to comment Share on other sites More sharing options...
GTEASER Posted February 13, 2023 Share Posted February 13, 2023 Tighten the clamps on the TMIC coupler hose to the throttle body, chances are they are loose. Or better yet, get rid of the stock one with the double layer whoopie cushion thingie and get the Perrin silicone hose. 3 GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
fxtgilly Posted February 16, 2023 Author Share Posted February 16, 2023 Just installed my GFB bov today, still getting the whistling noise and it’s still only making around 14lbs. Gotta say i’m a happy man regardless with this bov, it sounds awesome haha. when replacing I checked every vacuum line, every clamp or coupler I could, but it definitely doesn’t seem to be the bov itself. I attached a video that showcases the sound, as soon as it starts to make boost it makes that weird high pitched squeaky noise… I’m also wondering if maybe there’s something screwy with my AP? It’s targeting 16.9, but i’m pretty sure it’s still hitting the stock 14.5lbs or whatever that is. so maybe it’s not a leak, but a map issue? I definitely have the stage 1 93 ROM on it, but i’ll try flashing the stock map back on and see if it makes target boost when it’s stock levels. FullSizeRender.MOV Link to comment Share on other sites More sharing options...
GTEASER Posted February 16, 2023 Share Posted February 16, 2023 Dude, it's the TMIC coupler. Search this board for "farting sound". Remove the TMIC and cut the little liners out of the coupler as mentioned in the thread, then reinstall. 3 GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
fxtgilly Posted February 16, 2023 Author Share Posted February 16, 2023 8 hours ago, GTEASER said: Dude, it's the TMIC coupler. Search this board for "farting sound". Remove the TMIC and cut the little liners out of the coupler as mentioned in the thread, then reinstall. Thanks man, you were definitely right!!! Idk what they were doing, but I have a receipt of a shop having replaced this coupler, so earlier i had just checked the clams to make sure they weren’t loose. This morning I took the TMIC off, and the rubber part was super messed up, I don’t even think it was sealed around the throttle body at all. I took it off and put the intercooler with all the clamps back on. Unfortunately I think the ground to my fuel pump is messed up or something because it’s cranking and not starting now… gonna have to fix that when I get off work. 3 Link to comment Share on other sites More sharing options...
fxtgilly Posted February 16, 2023 Author Share Posted February 16, 2023 Apparently the crank no start issue was the entire engine harness plug, the little thing that keeps it locked in place had broken somehow, and i accidentally knocked it loose when I was taking the TMIC off... so i ziptied that back and everything's fine now. The coupler was definitely the problem. I was hitting 16.4lbs and not making the dumb noise! very happy about that, now I get to enjoy my obnoxious bov with peace of mind that my car actually works lol. Thanks for the help guys! 4 Link to comment Share on other sites More sharing options...
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