Gator GT Posted November 10, 2006 Share Posted November 10, 2006 Mods: this deals with both stutter and transmission/drivetrain. I didn't see a specific forum for transmission, just powertrain. So, seeing as I'm pretty sure this'll get covered under warranty (hoping), I posted here. Move as you see necessary. Thanks. Is it possible that our engine stutter (studder, hesitation, hiccups, etc) is breaking my 6MT? Yesterday, after a 2nd reset (I know, I know, ECU resets are incomplete solutions at best), I went on several pulls after letting it warm up fully. I have access to a private gently winding road that I used for this exercise. Go from 1st to 4th, 15 to 80, then let off the gas and engine brake, get on the gas and just drive it. Slow down, turn around and repeat. I did this 3 times. Then I took it out on public roads. I went out for 20 minutes, resulting in a 12 mile trek. During this trek, it did exhibit numerous stutters and hiccups. A pretty severe occurrence happened between 4500 and 5000 (which has happened before). Now, I did happen to drive a leftover 05 5MT wagon back in August. While I didn’t take it above 4k, I did push it up to 4k and did feel the infamous 05 stutter. You guys have it good with that one. I’d rather have that stutter all the time and incurable rather than have this. Upon return, during deceleration, I heard one of the scariest noises emanating from an AWD car with only 1500 miles on it: a metallic meshing whine. The noise was coming from in front of the shifter and was particularly loud in 2nd, but was there in 1st and 3rd too. This is well beyond what could be called typical gear whine. Commute is 14 miles, 20 minutes. When I left work to head home, it wasn’t there at first. But as I got closer to home, it started coming back. 2.5 hrs later, I head out for some in-town errands. Still there. Radio, radar and HVAC are all off, trying to hear it better. The loud RE050s aren’t helping. Anyways, as I pass by a building that is close to the street, I let off the gas and its very audible outside the car too. Sounds a touch worse on the outside. But now, as I’m driving with the windows down (and no one else around me to “taint” the auditory tests) I can start to hear it start/stop making noise as I engage/disengage the clutch while giving gas too. So, its not only happening during deceleration, but also during acceleration. Thoughts are center diff, gears/synchros (?) or clutch. I’ve preliminarily eliminated the front diff, since its an open unit and the center is going to see stresses before the front anyway (plus the center is a VLSD unit too). I’ve got a ride setup with a tech at 730am on Monday. I’m also putting in a formal complaint about the stuttering, which a customer service attendant told me that when I bring it in for the test drive, then that would be the time for the complaint. I don’t plan on letting them blow me off with the “it’s a turbo and that’s normal for this motor”. Bull. Why its normal for this motor is cause Subaru tried to have its cake and eat it too: produce a “performance” sedan that meets low emission requirements. Back to the stuttering and ECU resetting for a moment. I have noticed that after resetting the computer, its very aggressive and pulls hard…but also stutters hard. There seems to be a stutter in every 1,000rpm segment after 2k. Between 2 & 3, 3 & 4, 4 & 5; and it seems to be fine for the next 1,000. I have not taken it above 6k. This lasts for 2-3 days of regular commuting with some spirited legs inserted into that commute. After that, the stuttering smoothes out a touch and much to my chagrin, the motor feels less aggressive; like its pulled some power out of the equation. My fear is that if it is the tranny, and they fix/replace it, that it’ll only get broken again if it is the stuttering that’s causing the stresses. Does anyone know if FHI/SOA used an STI 6MT non-DCCD center diff in the B? So, finally, back to my question: is the stuttering causing breakage of my transmission/driveline? The fact that well after smooth engagement of the clutch (pedal out) I get into the gas and then it starts stuttering (fuel cut, timing pulled, whatever) power is cutout, transmission is “relieved” of its duty of transmitting that power to the wheels; but then when the motor comes back from its hiccup, throttle is still at WOT, telling the engine to resume putting out that same level of power and then transmits that level right back into the transmission, snapping things back to where they were. And keep in mind, this has all been done in Sport, not Sport #. Thoughts? Similar experiences? Should I be demanding a new tranny and ECU with allowance for aftermarket tuning (and I’ll even agree to tuning it to 250hp) that SOA will honor with original warranty? I mean, in all seriousness, if the ECU is making the motor hiccup and abuse the tranny, that is not my fault at all. And I’m just waiting for them to tell me that I shouldn’t be putting my foot into it. Oh RLY?!!? Thanks for your patience and time in reading this. "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
LIZARD Posted November 10, 2006 Share Posted November 10, 2006 Holy Post!!!! Is it stuttering or is it more of a "shudder" where the car hicups and shakes? Either way you should have that thing in and checked out!! Stage2.5376, TDC ProTune,blah blah blahhhh and....Alky/H20 injection Link to comment Share on other sites More sharing options...
Gator GT Posted November 10, 2006 Author Share Posted November 10, 2006 Holy Post!!!! Is it stuttering or is it more of a "shudder" where the car hicups and shakes? Either way you should have that thing in and checked out!! All of the instances of "unsmooth-ness" are one-fire stutters (hiccups and moves on) except for the 4500-5000 hiccup, where it feels like I've screwed up the engagement of the clutch....but I haven't cause pedal was let out back at 2500. Its like it gives up for a half second then comes back with its same fury...like a half-assed bucking. "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
brett s Posted November 10, 2006 Share Posted November 10, 2006 If you haven't already, double-check your tire pressure - incorrect differences between front & rear tire pressure cause all sorts of deceleration noise, because of the slightly different circumference. Link to comment Share on other sites More sharing options...
Gator GT Posted November 10, 2006 Author Share Posted November 10, 2006 If you haven't already, double-check your tire pressure - incorrect differences between front & rear tire pressure cause all sorts of deceleration noise, because of the slightly different circumference. Brett, thanks for the tip, hadn't thought about that. For the B, OEM spec on the door jamb: Fr: 33psi Rr: 32psi I just checked (having filled them preparing for the dipping winter temps about 2-3 weeks ago) and they are reading: Fr: 36.5psi Rr: 35.0psi I'll dump 0.5 psi out of the fronts, but I'm skeptical that it was the culprit. Again, thanks for offering logical advice. "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
VTGT Posted November 10, 2006 Share Posted November 10, 2006 Mine shudders. Its like a shaking and hesistation between 2-3k with tdc stage one. Everyone says its normal. I think it just has to do with the pressure plates in the 5eat. Link to comment Share on other sites More sharing options...
Opie Posted November 11, 2006 Share Posted November 11, 2006 The stutter will not damagae the driveline. The 6MT is a very well built tranmission, it's pretty hard to break. It sounds like you have some other problem causing your hic-ups Subaru will never authorize, nor pay an allowance for aftermarket tuning.... Link to comment Share on other sites More sharing options...
castor Posted November 11, 2006 Share Posted November 11, 2006 Opie... Any word on the 05 Stutter?? Any updates / fixes in the works??? The last flash didn't do much if anything. Thanks...and sorry for threadjacking. C Link to comment Share on other sites More sharing options...
Gator GT Posted November 12, 2006 Author Share Posted November 12, 2006 The 6MT is a very well built tranmission, it's pretty hard to break. Thats what I have heard/read for years (from the 04 STi on) and was assuming when they announced it for the 07 B. So imagine my surprise when this happened. "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
Gator GT Posted March 15, 2007 Author Share Posted March 15, 2007 bump. new thought...as the warm weather is back...and so is the meshing noise on deccel.....wondering if its bad lash from the factory?? "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
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