Hey 8 Club,

Ive been chasing this problem on and off around 8-9 Years. Not sure if this sound im hearing is the MIAC (Marbles in a can) or just some sort of rattle.

Car details:

2005 6MT
Pretty much Full Bolt ons

• D585 Ignition (extended leads and harness to move ignition away from hot engine
• modified AEM intake (4" to 3.5" to 3")
• Generic aftermarket header
• BHR midpipe
• HKS HiPower Exhaust

I say Ive been chasing this problem for around 8-9 years, this problem started in roughly 2015. I initially thought it was predetionation, but I wasnt throwing any codes nor had any performance issues. I always run 93 Octane gas.

Things I tried to remedy the issue circa 2015

• Clean maf
• Clean ess and reset nvram
• professionally serviced all 6 injectors

Later in the year the engine popped and it sat for a very long time. In 2018 I attempted to rebuild the motor myself (I failed) and in that process the LIM was dissembled and all the valves were cleaned and any vacuum lines or parts that needed replacing were replaced.

Fast forward to now, I purchased a lowish mileage JDM motor, Installed the motor with all the cleanish/refurbished parts (ie: LIM, UIM, CAI, Alternator, Injectors, etc) from the botched motor build and not surprisingly the noise is still there. Car runs fine, no complaints of any power loss. I was chasing a misfire on rotor 2 but that seems to have worked its way out.

I have ordered the heater core coolant flow reducer to rule out that it is the cause. It has not arrived yet.

Here is the sound, to frame the video, this is me down shifting from 4th to 3rd to 2nd then going WOT. The sounds seems to occur around 6000 rpm only at WOT. (sometimes seems like the sounds starts at 5700 rpm sometimes 6200 rpm, but only at WOT)