I Donated thefultonhow Posted April 5, 2012 I Donated Share Posted April 5, 2012 I'm on Infamous Rev01. He thinks I have a post-MAF/pre-turbo leak that is leaning me out and causing the knock. I've now checked, double-checked, triple-checked, and in some areas quadruple-checked my intake tract and all vacuum lines leading off it, and am having serious trouble finding anything that even looks like it could leak. I do not have a boost leak tester, and need to get one, but while I'm waiting on that, any comments on the log? I deleted all but the most important parts, since LGT.com limits CSVs to 160 KB, and the file was 1.4 MB.LearningView_4-5-2012 5 12 57 PM.csvromraiderlog_20120405_165117 for LGT.csv Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 get that boost leak tester. you are knocking harrrrrrrrrrd Link to comment Share on other sites More sharing options...
mr.hicksta Posted April 6, 2012 Share Posted April 6, 2012 http://www.turboboostleaktesters.com/servlet/StoreFront Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Does it matter which one of those Subaru testers I get? And/or can I get a certain size end cap from Home Depot and put a fitting in myself, and if so, what size? Link to comment Share on other sites More sharing options...
mr.hicksta Posted April 6, 2012 Share Posted April 6, 2012 I got the WRX one, and AFAIK you can piece everything together at Home Depot, but for $35 picking one up from that site is worth it IMO. Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 inlet size, i believe 2 1/4". the wrx tester will work...should Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Okay, you are supposed to attach the boost leak tester at the turbo inlet, where the after-MAF tube goes usually, right? When you do this, is the purge valve supposed to make a really high-pitched noise? If not, I think I found my problem. Â The purge valve is this thing, BTW:Â http://i14.photobucket.com/albums/a325/thefultonhow/Subaru/IMG_20120406_102711-1.jpg Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 yes its suppose to make a squeal sound, continue to put air into the system. the sound will go away. go to about 10psi, then listen for leaks. generally a 1psi/second leak is acceptable. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Dammit, I thought I found my problem! Â I put a hose fitting on the tester instead of a valve stem (it's what I had lying around), so I have no pressure gauge except on the compressor. Is it safe to turn the regulator on the compressor up over 20psi? Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 your air source can be from an air tool compressor, up to 150psi, thats why the boost leak tester hicksta linked has a gauge, so you know when enough is in the system. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Well, I'm under a 1psi/sec leak. But I'm still getting a crapton of knock. WTF? Are you sure 1psi/sec is in the acceptable range? (Not that I can figure out where the leak would be if that wasn't within spec -- I even tried the soap-bubble trick.)Â BTW, my peak boost is supposed to be 20.5 psi and I'm not getting there, either.romraiderlog_20120406_114619 for LGT.csvLearningView_4-6-2012 11 54 25 AM.csv Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 compression test? have oil consumption isses? Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 compression test? have oil consumption isses? I certainly didn't have oil consumption issues up until a couple weeks ago. I haven't been checking my oil more recently than that, until today, when the boost leak test popped my dipstick out and sent oil spraying all over my engine bay and garage floor. I had to add 2.5 quarts of oil after that, but I lost a LOT of oil before I noticed (I was fiddling with my air compressor at the time). Are you just saying "compression test" to throw it out there? I don't want to do one if I don't have to.  Keep in mind also that I'm only on Rev01. Infamous thinks I have a post-MAF leak and that's what's causing problems, but this shows that a leak is probably not the issue, right? Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Are you sure 1psi/sec is in the acceptable range? Can anyone confirm this? Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 well the boost leak test would show you boost/vac leaks. if you're saying the system is holding pressure well, (no hissing heard from around the engine) then it's safe to say its something else. a significant vac leak, like inlet, would literally drop the pressure like a rock. Â you clearly loaded too much pressure in the system if the dipstick went flying out. did you monitor the boost leak tester gauge? you loaded pressure inside the crankcase and it caused this. some say to take the oil cap off but frankly air will escape through it since the pcv system is in tact, so what i say is keep the cap on but pressurize the system lower. some people pressurize it to 20+psi. that's not necessary. 10psi is enough to monitor for system leaks. Â low compression in a cyl can cause oil to leak by(ringland problem), oil detonates when ignited, cause knock, causing your issues. it's never a bad test to do even if your car is healthy. it's literally the EKG of the heart disease patient. Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 if it's leaking at 1psi/second, and mine does this, maybe a little slower, you should be able to audibly track down where the hissing is coming from. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 I can tell there is hissing, but I can't track it down. It seems to be coming from somewhere under the manifold, probably on the turbo side, although I'm not sure on that. Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 Well now you have something to do tonight! If the gauge holds steady of 1psi/sec or better you're good. Mine leaks 1psi/sec and runs fine, af trims normal, no knock Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 6, 2012 Author I Donated Share Posted April 6, 2012 Well now you have something to do tonight! If the gauge holds steady of 1psi/sec or better you're good. Mine leaks 1psi/sec and runs fine, af trims normal, no knock Well, it leaks less than 1psi/sec as far as I could tell. I'm thinking more and more that this is an issue with the tune. I don't even start knocking until 5000+ rpm anyway, and boost is tapering by that point. Link to comment Share on other sites More sharing options...
bmx045 Posted April 6, 2012 Share Posted April 6, 2012 then timing needs to be pulled. i knock in similar places Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 15, 2012 Author I Donated Share Posted April 15, 2012 Could the plug for the knock sensor tapping against the block register as knock? It's plastic, so my hunch is no, but I'm trying to track down why I'm knocking so much on startup (34 knock events in a few minutes of driving with only a second or two of WOT -- the attached log has the first 15, and I wasn't even boosting yet), and I'm wondering if it's false knock.romraiderlog_20120412_163806 startup.csv Link to comment Share on other sites More sharing options...
B-BGTLimited Posted April 16, 2012 Share Posted April 16, 2012 You'll probably see more knock at part throttle from other drivetrain noises or just the fact that your at a lower RPM and loading the engine a bit. That knock is not as bad as something when your at WOT. I'll get counts like this driving around and shifting constantly for traffic and leaving lights and such. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted April 16, 2012 Author I Donated Share Posted April 16, 2012 It might also have something to do with my turbo dying. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.