That "on-off-on" cause is in direct opposition with my driving habits. I shift slowly to preserve the synchros in the tranny, as well as the engine mounts; the RPMs on this car drop rather slowly as a byproduct of tuning for emissions purposes and a heavi-ish flywheel.

I do, however, do a "on-off-on" to induce rotation mid-turn, without shifting. In other words, I'll lift on the throttle and get back on it to upset the car's balance.

Has anyone successfully captured the knocking sound?

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It has been seen via data log. Check CSG mikes thread. The last few pages has some data log screen shots.

[ame="http://www.youtube.com/watch?feature=player_embedded&v=450Pov98STg"]BRZ bad idle + misfire, no CEL, stock engine - YouTube[/ame]

You can hear it "pop" at the dips.

Roger that. :thumbsup:


(The TSB used the word misfire. That is why I used it in my post.)

Right. After periods of detonation resulting in seal failure, the cylinder will lose compression around the injector which results in a misfire. ;-)

Mine never popped at idle, but once you give it a little throttle in any gear it sounds like the 4th of July. Firecrackers going off left and right.

Mine only pops at idle and only at temperatures lower than 65*F so far (so more likely in the winter)

Do you guys think it still could be the same issue? Is there something about these seals that is temperature-variant?

Here's a video a posted a while ago:
http://www.youtube.com/watch?v=Ky_vDK4ePHI

Your injectors should be okay as long as you don't hear any popping under moderate acceleration.

And is my understanding correct that the AFR is subsequently too lean resulting in even higher combustion chamber temps, which ultimately leads to burned pistons and a destroyed engine?

Track driving would likely exacerbate the problems either from initial high operating temps and/or persistent high operating temps, much higher than one would likely see in brisk road driving.

Is that what's happening here?

Looks like I'll be off the track until Subaru/Toyota make the ECU flashes official :(

Very interesting. :thumbsup:

So, let me see if I have this straight. We're talking about detonation caused by a fuel/octane issue (?) or an incorrect-from-the-factory timing issue (?). Either way, a software update that adjusts the timing might/will fix it.

The reason that a track car might blow up under this condition and the same car driven on the street might not has to do with a slightly increased temperature achieved on the track (?).

Right, but once the seal is blown, the ECU flash won't fix it. The seal will need to be replaced at that point.