Libacy GT Posted September 30, 2017 Share Posted September 30, 2017 Hi a while ago , After shop installed a racer x Charge pipe, hybrid turbo, and 3port BCS, I developed a rattling sound (like metal on plastic , or some metal in a can sound) Things ive observed when the sound comes on. 1. under 2100rpm 2. off boost , goes away as boost starts after about 2100rpm (noticed boost target on bttsm app under 0.7 psi when sound is on) 3. car is usually under load from 3rd, 4th, or 5th gear. 4. This sound has sometimes triggered FLKC on my btssm app, on one night i tested, every time the rattle came on, the flkc got triggered to -1 or so. i can keep the sound constant if i stay around the 2100rpm range and under load. Most likely not the engine and turbo as i have since installed new engine and now have the stock turbo and the sound is still there. Although Racer X pipe is very close to brake lines and air box, i have put rubber in between all possible hitting points and the sound is still there. So dont think charge pipe is hitting anything. I have noticed slight fuel smell in cabin area. But there are no exhaust and Air leaks AFAIK as everything was tested after new engine and tuning I am seeing the mechanic soon for the first service after engine was installed, i would like to hear your suggestions as to what it could be so i can mention it to them Could it somehow be boost controller related? Or torque converter bearing? Link to comment Share on other sites More sharing options...
jojorios Posted September 30, 2017 Share Posted September 30, 2017 Heat shield maybe? Before I got my headers switched out I was having some bad rattling due to the the heat shield being massively corroded. I am also now beginning to get a new rattle sound which I haven't' been able to pin point but if I hit the downpipe with my fist, I can hear it coming from wounds like the header/downpipe connection area. I'm not sure what may be in that location to cause it. Sounds external though. Link to comment Share on other sites More sharing options...
MilesA Posted September 30, 2017 Share Posted September 30, 2017 I agree on the heat shields. That is so common, especially with age and miles on these cars. There are certain conditions that trigger a resonance in the exhaust. That is the first thing I would try to rule out. Link to comment Share on other sites More sharing options...
Libacy GT Posted September 30, 2017 Author Share Posted September 30, 2017 Rattling heat shield can trigger flkc? Sent from my HTC_M10h using Tapatalk Link to comment Share on other sites More sharing options...
Libacy GT Posted September 30, 2017 Author Share Posted September 30, 2017 When we say heat shield, heat shield over what exactly? Sent from my HTC_M10h using Tapatalk Link to comment Share on other sites More sharing options...
MilesA Posted September 30, 2017 Share Posted September 30, 2017 When we say heat shield, heat shield over what exactly? You have a lot of stamped sheet metal pieces mounted around the various pipes in the exhaust system and the turbo. These can corrode or the fasteners holding them in place can corrode and they will become loose. It will help if you can get the car up on a lift (or rack or hoist or whatever it's called in Australia). https://www.quirkparts.com/auto-parts/2010/subaru/legacy/2-5gt-trim/2-5l-h4-gas-engine/exhaust-system-cat/heat-shields-scat https://www.quirkparts.com/auto-parts/2010/subaru/legacy/2-5gt-trim/2-5l-h4-gas-engine/engine-cat/turbocharger-and-components-scat Link to comment Share on other sites More sharing options...
robburns201 Posted September 30, 2017 Share Posted September 30, 2017 Over the Turbo,Headers/Crossover,And any place along exhaust under the car... What he said!!!!^^^^^^^^ Link to comment Share on other sites More sharing options...
Libacy GT Posted September 30, 2017 Author Share Posted September 30, 2017 OK thanks for the info. Will get it checked out. Sent from my HTC_M10h using Tapatalk Link to comment Share on other sites More sharing options...
02LGTSNJ Posted October 2, 2017 Share Posted October 2, 2017 My rattle was coming from the turbo heat shield. A bracket had rusted thru and the metal on metal vibration caused an annoying noise. I jammed some exhaust wrap tape in between and it eliminated it ever since. Link to comment Share on other sites More sharing options...
Libacy GT Posted October 3, 2017 Author Share Posted October 3, 2017 (edited) My rattle was coming from the turbo heat shield. A bracket had rusted thru and the metal on metal vibration caused an annoying noise. I jammed some exhaust wrap tape in between and it eliminated it ever since.Would the noise be there at a specific rev range? And would it disappear when revs go up? Sent from my HTC_M10h using Tapatalk Edited October 3, 2017 by Libacy GT Link to comment Share on other sites More sharing options...
02LGTSNJ Posted October 3, 2017 Share Posted October 3, 2017 Yes, basically i would hear it right before I would shift into the next gear up. Link to comment Share on other sites More sharing options...
MilesA Posted October 3, 2017 Share Posted October 3, 2017 ...There are certain conditions that trigger a resonance in the exhaust... RESONANCE 1b (1) :a vibration of large amplitude in a mechanical or electrical system caused by a relatively small periodic stimulus of the same or nearly the same period as the natural vibration period of the system. Vibrations from the engine at certain RPMs have the same natural vibration period as parts of the exhaust system. This sets up the rattling sound you hear. That's assuming this is what's causing your noise. Link to comment Share on other sites More sharing options...
Libacy GT Posted November 16, 2017 Author Share Posted November 16, 2017 Just to update, we are confident the rattle noise is Infact a damaged torquconverter. I have valve body codes and torqconverter codes thrown and car went into fail-safe mode the other day. Also in drive/idle the car is getting very rough and it's not engine related as I have a new engine. All heat shield checked as well, so most likely it is torque converter on the way out Sent from my HTC_M10h using Tapatalk Link to comment Share on other sites More sharing options...
Becks1818 Posted November 19, 2017 Share Posted November 19, 2017 Identical description of my rattle (GT,6mt). Which turned in my a louder rattle and catastrophic engine failure. Go get it assessed at a Subaru performance shop before it's too late. You can find my build thread near the top of the fifth gen area Sent from my SM-G930W8 using Tapatalk Link to comment Share on other sites More sharing options...
Libacy GT Posted August 9, 2019 Author Share Posted August 9, 2019 Damn forgot to update this thread. Sorry guys Only recently found the source of the rattle anyway lol. Was actually the after market boost solenoid/controller hitting what ever was next to it. So they just bent the bracket slightly to get it out of the way and all good. I did end up changing valve body because that was dead, but torque converter was fine. Sent from my HTC_M10h using Tapatalk Link to comment Share on other sites More sharing options...
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