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Discussion Starter · #1 ·
So I just got my rebuild back and 500 mile break in oil change. I notice that there is a little rattle and it sounds like a coat hanger or loose wires shaking in front of the firewall driver side. It rattles 3x if I accelerate (just giving throttle at all really) at low RPM and the same noise when I let off the gas. Especially noticeable at RPM that is really too low that I should be upshifting. I figured I would try and see all ranges. At High RPM I can’t hear the noise.
Also a springy noise (like a playing card in a bicycle wheel) once when I went to drive off from a parking spot... maybe the pressure plate sticking or something ? I drove it a few miles home having to start and stop and it did not repeat itself.


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If it has forged Pistons you may be hearing piston slap

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Discussion Starter · #3 ·
I went with OEM EJ257 shortblock , I thought it may be knock, could I tell that on the AP? would it only be heard at low RPM like it is starving ?


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If you are starting at super low rpm you may be hearing misfiring and chugging because the engine is struggling.

Does it feel like it's chugging?

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Discussion Starter · #5 ·
If you are starting at super low rpm you may be hearing misfiring and chugging because the engine is struggling.

Does it feel like it's chugging?

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I don’t start at super low RPM but when it is borderline chugging around 1900-2000 in second or third gear I can make the noise consistently by hitting and letting off the throttle, it is always 3 times that it “rattles”. It sounds literally like it’s directly behind the speedometer, like really close to firewall or whatever. I am probably going to drop it off tomorrow night.


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I would start by not pegging the throttle at 1900 rpm in 3rd gear over and over.

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I can't say because I can't hear it. Take it to the builder and ask. Did they tune the car? The ej257 has different Pistons than the ej255 and the heads may have different volumes as well, I don't know. However I'm almost certain it would need tuned for.

If not you could be having some low rpm missing or something.

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Discussion Starter · #10 ·
I can't say because I can't hear it. Take it to the builder and ask. Did they tune the car? The ej257 has different Pistons than the ej255 and the heads may have different volumes as well, I don't know. However I'm almost certain it would need tuned for.

If not you could be having some low rpm missing or something.

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I have a base map put together for the break in. Dyno in 1250 miles !


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Discussion Starter · #11 ·
I can't say because I can't hear it. Take it to the builder and ask. Did they tune the car? The ej257 has different Pistons than the ej255 and the heads may have different volumes as well, I don't know. However I'm almost certain it would need tuned for.

If not you could be having some low rpm missing or something.

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Update : Went up on a lift, things were tightened. Mechanics think maybe that it is something in the transmission or firewall. Second place I brought it to was a transmission shop. They said that it could be something in the bellhousing, starter (gear?), something touching the firewall with the torque from the engine, flywheel (? )
There is no set RPM or gear range but it does get pronounced when going up the slightest incline while cruising. Nothing when clutch in or bumps, nothing on decel after the initial let up, nothing through the rpm range unless going up an incline. No clutch slip... the mystery continues !


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I've been told that the knock sensor on cylinder 4 is sensitive. However I had the same issue until I replaced my rear of sensor.

I don't want to say it's ok, but I don't think it's bad.

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Anytime I leave my STi at idle the cyl 4 knock count sensor goes nuts... read up a little and you'll find the "knock count" is almost useless on your AP.

Watch your DAM, Fine Knock Learn, and Feedback Knock, and if they're good, you're good.
 

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Discussion Starter · #16 · (Edited)
Anytime I leave my STi at idle the cyl 4 knock count sensor goes nuts... read up a little and you'll find the "knock count" is almost useless on your AP.

Watch your DAM, Fine Knock Learn, and Feedback Knock, and if they're good, you're good.
-1.40 feedback knock/ 3.15


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