HansGT Posted February 11, 2011 Share Posted February 11, 2011 Link to comment Share on other sites More sharing options...
compsurge Posted February 19, 2011 Author Share Posted February 19, 2011 I took it to IAG first thing this morning. They got my boost leak issue under control, and I proceeded on my way home. About 57 miles out, it started pulling timing, so I pulled over and heard some sort of cadence noise coming from #3 cylinder (passenger right side). Fearing rod bearing issues, I had it towed back to IAG. This was not the case as far as they could tell. Car got squeezed in and they compression tested - all 4 cylinders @ 140psi. They said it did sound like it was misfiring very slightly. I can hear it, and it occurs after warmup/open loop. They adjusted plug gap to 0.029" and said they couldn't replicate my issue again. I went on my merry way home. Only, this time, after about 90 miles, car started acting up again. I pulled over, car making same cadence noise (I later successfully captured it in a audio clip - end of post). I continued to drive home, when it magically cleared out and acted fine after a while at sustained highway speed. It then surfaced again after a bit and stayed until I shut the car off. So far, I have deduced that the issue arises when at low speed after sustained driving at highway speed/engine at temp - could this be a heat related issue? Injector issue? Coil Pack? Coil pack grounding out on block (what does this mean, I found it on a youtube video comment)? Oil pressure? Banjo Bolt (on order ) filter about to clog all the way? Ever-so-slight rod knock? I've already pulled timing covers and examined the belt and cam marks - it is as it should be. note: I am running bare turbo/no heat shields (will be ordering PTP blanket). I have to mod my oem heatshield more to fit over the CNT DP as well. I am at a loss here. Car was running absolutely perfect when I left IAG, and now it's back to doing this crap. Sound clip: What is this sound reminiscent of? The closest analogy I can make is fingers tapping a desk (about the same volume). https://docs.google.com/leaf?id=0B5ADKfDhsM1-MDZlOTUyOGMtMDVlZC00OGU4LWI4ZTctZGI1OWNkZjI1ZTA5&hl=en&authkey=CKyM2OMH Link to comment Share on other sites More sharing options...
iNVAR Posted February 19, 2011 Share Posted February 19, 2011 Where are you located and what's the temperature like? Link to comment Share on other sites More sharing options...
compsurge Posted February 19, 2011 Author Share Posted February 19, 2011 MD, was 73-77 on intake temp IIRC. also, edited post above to make sense. Link to comment Share on other sites More sharing options...
compsurge Posted February 19, 2011 Author Share Posted February 19, 2011 I just listened to the clip. It appears my editing skills are very bad at night. That clip is NOT the sound - that's just normal valvetrain noise. This one is more like rod knock only muffled. Maybe I have tinnitis or something??? I can't hear it any more on the entire sound clip. I am not imagining things! Link to comment Share on other sites More sharing options...
compsurge Posted February 19, 2011 Author Share Posted February 19, 2011 https://docs.google.com/leaf?id=0B5ADKfDhsM1-NzFmYjgyYWMtMzI4MS00NGMwLWE3ZGQtOWVhOWE4Yjc5ODRh&hl=en&authkey=CPm1gKwL I had to listen a lot harder today. I made this modified version of the previous clip that is isolated and slightly amplified over the valvetrain noise. I am thinking ever-so-slight rod knock at this point. Link to comment Share on other sites More sharing options...
compsurge Posted February 20, 2011 Author Share Posted February 20, 2011 I'm going to plug in romraider and see if I can capture the cylinder roughness. Maybe an injector is not flowing right in a certain demand region and is causing some sort of actual knock event to occur? Link to comment Share on other sites More sharing options...
compsurge Posted February 26, 2011 Author Share Posted February 26, 2011 Did some data logging with Rom Raider (and lost the log of actual data? I just had parameter headings ). Long story short, I have no cylinder roughness, and I was able to get a knock reading in the 1500-2500 rpm region. I'll have to relog and figure out what I didn't do right. Non-Nija Edit: I also recollect that if IAM / DAM is at 0.9, I have zero knock issues. I am leaning towards this being an actual gas/tune issue and not a mechanical issue atm. More logging will be required to prove this, but I'm almost ready to burn the cost for an infamous tune to eliminate a variable. Anyone suggest I replace my front oxygen sensor? Link to comment Share on other sites More sharing options...
TSiWRX Posted February 27, 2011 Share Posted February 27, 2011 This is definitely way over my head, in terms of tuning/mechanicals. But I do want to butt my head in here to say something - please, if this isn't right, those of you with more experience, please, please do call me out on it, and correct me! OK, so, here goes: Stop switching fuels, including fueling stations and putting in MMT-rich additives. My car (typical "Stage II" by Tim Bailey, on ECUTeK) is *very* fuel-sensitive. I know for a fact that one of the three shell stations around me sometimes suffer for the "quality" of their V-Power 93. Of the some 8 or so times I've visited that station in the last 4 months or so, I've had 3 instances where my car almost immediately saw some serious -KC action, along with knocksum increment, as well as, once, actually having pulled down the IAM. Yeah, I've stopped using that station, completely. Including both these instances as well as of my experiences in the past, my car also responds very aggressively in "coming off higher octane gas," as in the follow-up tank to the "skunked" one to which I've added a good, MMT-rich additive for "rescue." During that follow-up tank, I'll often see some level of negative knock correction, but it works itself out, correcting to zero, without pulling down the IAM. It's my most humble opinion that you need to keep your fuel-quality issue at least consistent, during this troubleshooting process: that by altering where you're getting your fuel and pouring down additives in an effort to "rescue" perhaps a bad fill-up, you might be adding another variable into the mix. Best of luck! <-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges '16 Outback, '16 WRX, 7th Subaru Family Link to comment Share on other sites More sharing options...
compsurge Posted February 27, 2011 Author Share Posted February 27, 2011 Thanks for the input. Fuel has been consistently 93 octane Shell from one of two Shell stations here. Maybe for S&G I'll try Sunoco (I have not yet). If it ends up being a gas issue, I'm going to be flustered. Link to comment Share on other sites More sharing options...
TSiWRX Posted February 27, 2011 Share Posted February 27, 2011 ^ Ah, gotcha. Sorry, I must have mis-read, in trying to work through this entire thread. I had thought that you had a handful of different stations mixed in there. My bad. <-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges '16 Outback, '16 WRX, 7th Subaru Family Link to comment Share on other sites More sharing options...
compsurge Posted February 27, 2011 Author Share Posted February 27, 2011 Nope! Still a positive contribution though. My fuel habit is Shell. I refilled at a Shell station on Thursday, so it is actually pretty possible that station is the culprit. I remember that my last tank was at the other one. Maybe both are bad (and one is worse)! I wish I knew what to do to test fuel quality. Maybe they are ripping off the consumers! Link to comment Share on other sites More sharing options...
TSiWRX Posted February 27, 2011 Share Posted February 27, 2011 ^ I hear ya. I like to think the best of people, though, but I also can't help think that someone may be taking a shortcut, somewhere along the line: i.e. why else would that one particular station that I go to be the culprit, time after time? That's not to say that in the now nearing some 6 years I've had my car, that I've never gotten "skunked" gas from my "usual" station. It's just that it's happened much, much less frequently. <-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges '16 Outback, '16 WRX, 7th Subaru Family Link to comment Share on other sites More sharing options...
compsurge Posted March 1, 2011 Author Share Posted March 1, 2011 After reading the entire internet, I have concluded that after verifying the engine has good compression, there are no boost leaks, and has no cylinder roughness. I think I'm going to just have Shamar run with the assumption that this is just noise, and up the knock threshold to apparent '08 WRX levels of >0.8 g/sec load. Of course after I try Sunoco and install the oil pressure gauge I bought. Link to comment Share on other sites More sharing options...
compsurge Posted March 12, 2011 Author Share Posted March 12, 2011 Update: after more internet research I think I stumbled across the exact symptoms: bad Dual-Mass Flywheel (marbles in a can sound near FW/end of engine, some clunking at startup). Excited. Will check to see if I can test the flywheel play today. Link to comment Share on other sites More sharing options...
SPONGEM Posted March 23, 2011 Share Posted March 23, 2011 Hello Hi I'm new here but not new to turbo cars... I had an stage 3+ audi a4... I had those similar symptoms once and found that running a step colder plug and closing the gap eliminated most of the knock and replacing my MAF and ICM totally cured the knock... Hopefully you identify the problem soon... Hate those small but potential expensive problems that take so much time to identify... Link to comment Share on other sites More sharing options...
Mo_GT Posted June 1, 2011 Share Posted June 1, 2011 Did you manage to find out if it was the flywheel? Link to comment Share on other sites More sharing options...
compsurge Posted June 2, 2011 Author Share Posted June 2, 2011 I will hopefully getting this part completed this month due to time constraint. I finally am freeing my schedule up and it's the heat of summer. Go figure. It's perfect car project time! I can hear something from the drivetrain making noise (definitely some clutch chatter/flywheel clacking). It is very faint though. I am going to triple/quadruple check all the installed Group N mounts. I may also, for sanity, buy a new knock sensor and upstream oxygen sensor. Link to comment Share on other sites More sharing options...
compsurge Posted July 18, 2011 Author Share Posted July 18, 2011 Back from the dead: I'm going to order new swaybar and end links. I have finally put the pieces together and I believe the swaybar bushings up front are worn (there is ~1/8" gap between the bar and the bushing now). My end links are also possibly bad. I paid closer attention to my AP as I was driving and noticed it pulled timing on every single bump. I also took it down a road under construction and by the time I returned to the better road, I was in limp mode. (and have been driving close to, if not at IAM of 1 prior to that). Might as well use this as an opportunity to upgrade! Whiteline adjustables, here I come Link to comment Share on other sites More sharing options...
HansGT Posted July 18, 2011 Share Posted July 18, 2011 subscribed Link to comment Share on other sites More sharing options...
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