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Old 12-29-2012, 12:12 PM   #11
Nickcrsx
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Join Date: Dec 2008
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Quote:
Originally Posted by jason02wrx View Post
Knock Sensor sir!

My 02 had the same issue as you. Started out at first only when high humidity/rain. As soon as you touch the gas it pulls -12* and DAM goes to ****. There will be a CEL soon...
Thanks for the post! The day I got in the car it was rainy as hell and super humid. I will take a look.

Quote:
Originally Posted by Uncle Scotty View Post
take the oil filler cap off with the engine running

does it blow smoke???

yes = its done, stick a fork in it



this is classic rod knock symptoms


and you dont yank out the injectors to do a compression check
Good simple test. And yes I know how to do a compression test, haha. I was simply referring to pulling the injector to make sure the o-ring was properly seated. Will do this first thing. Thanks Uncle!

Quote:
Originally Posted by FRWRX View Post
OK, just few questions :
The long block has been changed so you have removed the knock sensor from the previous engine and fitted it onto the new engine. Are you sure you use the correct torque to fit the sensor ?
You didn't log the VVT. Did you make any modification in the maps in regards to VVT ?
What about timming belt ?
Awesome question! VVT is stock and timing belt is brand new w/ all components. As for re-checking the knock sensor, I will take a look ASAP. You are correct in that the knock sensor is from the old block, and over time may have developed a problem from being removed and re-installed.

Quote:
Originally Posted by Ziggyrama View Post
Some food for thought, stock STI does not listen for knock below 0.9 or 1.0 load, depending in which direction you're transitioning in or out of the listening range. What are your threshold set at? Before everybody jumps down my throat on how crappy the stock tune is and all that, the low load timing maps are not that bad. So, why Subaru would do that? It's possible that the sensor may be picking up lots of false knock under low load due to resonances in the engine bay and sounds being interpreted as knock. The knock sensor is nothing more than a microphone whose signal is fed into an analyzer that looks for knock signatures in the feedback. OP, search for false knock. You'll see many threads of people pulling their hair out about this. Low load, cruising situations, crazy FBKC. Makes no sense. Some anecdotal evidence, I tried lowering my listeing thresholds down and it produced exactly what you're describing. My logs started to show major knock events and ECU constantly pulling timing at loads <1.0. ECU would pull timing, more knock, more pull, more knock. That was a year ago. I went back to stock level thresholds as there seems to be more to it that meets the eye. I am actually willing to give Subaru the benefit of the doubt on this one. Now, I am not saying that you're fine. Just pointing out that it's possible that you're chasing a ghost. But, you should investigate to make sure you don't have a problem. If you have an EGT gauge, look at your temps during those events. If they're high, you may not have enough timing.
This post is epic,thanks so much.

Few points:
-Knock that low in the G/rev range doesnt make sense. The problem is that I kept the thresholds at a stock level. Now the car has full torque solutions motor-mounts. Now they never produced a problem before I changed the injector o-ring so I dont suspect they are the issue. I have checked the engne bay many many times for something causing ambient noise levels that the knock sensor would pick up and produce knock like symptoms.

-As for EGT's being high, you bet! I guarantee that EGT's are massive due to IAM being at zero and running base timing right now. Just to be safe I am not going to disable the knock sensor under 4100rpm and run the risk of potentially melting a valve.

-Your post has me thinking. Chasing ghosts is typically what I do. Ha. I am going to take a triple check at whats going on in the engine bay and look for rattles, etc. From there I think I will take a look at the actually knock sensor and see what the hell is going on.

Quote:
Originally Posted by jaxscuby View Post
if its not done..blown up..piston failure due to a lack of fuel.

i would double check anything that the engine is bolted to
or bolted to it.
Thanks. And always a possibility.
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