Engine Noise ~3k RPM

Normally I hate these threads but I’m a bit stumped. 2018 off-road MT with 104k miles. Noise started a couple weeks ago but was much quieter at first, barely noticeable unless you were paying close attention. Now it’s pretty obvious.

As I accelerate the motor to ~3k RPM (both in gear or in neutral), I hear a higher pitched noise that coincides with the normal motor noise. Thing is, it doesn’t stick around long. If I lift off the gas slightly or just hold 3k for a few seconds, it goes away. Seems like it sticks around longer if it’s in gear but only because the rpms are a bit more stable.

In the video, you can hear the noise, about 9 seconds in, it stops.

Normally I’m good at figuring out issues but no clue on this one. Doesn’t sound like A/C compressor whistle, doesn’t really sound like an idler pulley (gonna pull the serp belt today and check them out. Serp belt was changed 2k miles ago). I guess the good news is that the noise isn’t sustained. Just hoping it’s not internal head noise or something..

Edit: updated video
https://youtube.com/shorts/-Dwow1Y7WP0?feature=share

 

Wouldn't you know...its friday.

 

i think you are just hearing the VVT-i system.
https://dannysengineportal.com/vvt-i-variable-valve-timing-how-does-it-work/

 

The problem is that it’s a very new and obvious noise (not as obvious in the video) but I’ve heard how this motor sounds for years and know it’s not normal. I wish it was just VVT.

 

Could just be the serpentine belt.

 

Am I deaf? I don’t hear anything abnormal.

 

New belt, only 2k miles or so on it. I remember how the old belt sounded but this sounds quite a bit different. Gonna pull the belt anyway to inspect everything. Was hoping it was one of the idler pullies but you’d think that would be a much more consistent sound.

 

Nothings worse than trying to capture noises on phone video.. man, in person it’s so noticeable haha. The noise ends about 9sec into the video.

 

Nothing is normal about these turd gens

 

Why not film under the hood where the noise is. Kind of sounds like someone installed a turbo from the video.

 

I cant hear the noise in the clip either. Could be lots of things, fuel injection nozzles, hydraulic lifters, belt, pulleys, etc. As the noise gets louder, it may get easier to diagnose. It could be a new permanent noise. My engine seems to tick louder than when new. The ticking hasn't got worse and truck drives good otherwise - no oil burning and engine response remains good.

Edit - I hear it now, the engine smooths out at the end of the sound clip. That is different. I’m thinking add fan clutch to possible source. That and the pulley bearings can be diagnosed in one shot. Remove the belt and run engine for 20 seconds to see if the noise goes away.

 

Tape you phone to the inside of the hood and press record. Drive around for a few days and upload it, may help a bit.

 

I rarely run my engine at 3k to start with.

 

That I agree with. I have the whistle and your noise isn't like mine at all

 

Haha love that you guys have a sense of humor

 

Particularly on Fridays

 

Update:

Took the belt off, didn’t hear anything but it’s also hard to replicate the sound when the engine is cold and obviously I can’t run it long without turning the water pump. Put the belt back on, took it for a drive to warm it up and got a much better audio of it. Forsure seems like a belt / pulley issue, thoughts? Replaced the belt a couple thousand miles ago, inspection of it seems in perfect condition still.

https://youtube.com/shorts/-Dwow1Y7WP0?feature=share

 

Years ago I had a fan belt clutch go and it sounded like hell. I'm no mechanic but it's a guess.

 

strange, that’s near peak torque and our motors seem to really like being near 3k (or just shy of it). Yours a manual too?