Weird Rhythmic sound coming from engine during idle/RPM changes.

Hi guys, Thank you in advance for taking a look (Or more so "Listen").

Vehicle: 2008, Toyota, Tacoma. 2.7 L engine. 186K miles. Manual Transmission. Well taken care for.

I'm posting a couple of video's below, and it's a similar issue. I've been having a weird sound coming off my engine when I increase and decrease the RPM's during neutral and when in gear. It's a "revving", rhythmic sound. No "slippage" occurs with clutch use, and gear shirting is normal. It's only during changing of speeds and RPM's of the engine. There's not too much to add to this description. Overall, does not appear to be effecting the drive performance of the truck, but this sound has really "ticked up" in the past 1000 miles or so. Again, Thank you for your honest advice.

https://youtube.com/shorts/mta3-ueAAhA

https://youtu.be/6Vx3rw_O42U

 

You took the belt off...

 

Sorry, can you clarify this? What belt are you referring to? The Serpentine Belt?

 

The Drive Belt....it could be a belt tensioner pulley ,water pump..etc.

 

Ok, thank you for the clarification! I'll take a look at the belt and try to see what's going on. When I looked at it briefly, it was taut and didnt appear to have any problems, but I'll dive deeper into checking it out. Thanks for taking the time to give it a listen!

 

Turned out to be my Alternator! Swapped it out, and the sound magically disappeared