Screeching/grinding sound when applying sudden pressure to throttle

[RZNT4R]

Absolutely no development whatsoever.

When I started looking into this I got caught by the arrival of winter and honestly work has NOT let up since then, what vacation I had I spent mostly sleeping. Mathematically, the time is there to look into it, but the energy level isn't there lol.

Since driving the BRZ I'm at least comfortable with the noise, I'm still curious, but it's a lower order of priority now

[chipmunk]

First I thought I knew what rattle you were talking about, but the more I read these posts, the less confident I am.

If it's valvetrain related, can you reproduce the same noise with 0W-20 oil as well as thicker 5W-30, or even 10W-40?

I had always assumed that, since the operating range is between 3000-5000 rpm, everything under 2000 rpm is considered "lugging", and that's why I heard those unusual rattles.

Sent from a potato

[castroneves]

Sorry to resurrect an old thread, but did you ever get to the bottom of what this is? Mines starting doing it recently.

[RZNT4R]

Originally Posted by castroneves

Sorry to resurrect an old thread, but did you ever get to the bottom of what this is? Mines starting doing it recently.

You know how I said busy work and energy level etc? I'm looking at the date of my last post and oooooh boy have things been hectic since :lol I've barely had time to change the oil, I even did a first ever and sent it out for an interior detail because it had been accumulating 2+ years of filth from having no time to do it myself.

I'll say this though, oil viscosity and octane rating does not seem to affect the noise, or maybe I already said that? The sound also doesn't seem like it's coming up and out of the intake tract, and changing the intake had no discernable effect.

[castroneves]

Originally Posted by RZNT4R

You know how I said busy work and energy level etc? I'm looking at the date of my last post and oooooh boy have things been hectic since :lol I've barely had time to change the oil, I even did a first ever and sent it out for an interior detail because it had been accumulating 2+ years of filth from having no time to do it myself.

I'll say this though, oil viscosity and octane rating does not seem to affect the noise, or maybe I already said that? The sound also doesn't seem like it's coming up and out of the intake tract, and changing the intake had no discernable effect.

Thanks for the reply! Given all your findings and the number of others reporting it, will chaulk it up as benign, it just sounds like it shouldn't be there!