Gut Check, what's this noise?

1st Gen 4 banger pros, I need you!

My truck died 80 miles after hitting a quarter million. So I tossed money at it, and basically did an over haul outside the block. I have this noise now, which it did not have before, and I'm afraid it's the timing chain. The only other thing I can think if is water pump. The sound is coming from the front/top of the engine, but I'm hoping someone has heard this very same noise and can steer my down the right path to explore.

https://youtu.be/mQVRiuAPMsA

https://youtube.com/shorts/Z8_2s05Lz3w?feature=share

Let me know what you think. The following items were serviced or replaced.

• Valve clearances checked (4 shims replaced)
• Water pump
• Oil pump rotors
• Harmonic balancer (old one was starting to wobble)
• Crank sensor
• Cam sensor
• Oil pressure sensor
• Coolant temperature sender
• Starter
• Alternator
• Battery cables
• Vacuum lines
• Valve cover and gasket (brand new from LCE)
• PCV
• IAC Valve (new)
• EGR Valve and modulator
• Charcoal Canister
• Radiator
• Flex fan installed
• LCE header
• Rebuilt fuel injectors (serviced by Mr.Injector)
• Coolant hosed
• Thermostat
• Fuel pump
• Fuel filter
• Fuel pressure regulator
• Spark plugs and wires
• New coil packs

 

I'll be honest, I don't really know much about these 4-bangers, but that second video sounds just like what my idler pulley sounded like (on my 5vz) when it went. Do you have an automotive stethoscope? It'll really help you differentiate exactly where that noise is coming from (i.e. what area of the engine it's coming from).

 

Just a simple and very general suggestion: consider disconnecting the fan, etc belts.

If the sound goes away, you’ve narrowed down the possibilities significantly.

 

Sounds like the bearing in the idler pulley, or one of the other pulleys,,, I've heard alt. sound like that in the past, any kind of pulley.
Like was said, take the acc. belt off and see what happens sound wise, but the stethoscope will help a lot.

 

Sounds like vibrating metal. Does sound change if you increase rpm's?
Spray soapy water on belts, and see if the noise disappears.
Next test is buy or rig up a stethoscope with end able to listen to different parts of
front end. Many moving pulleys up front.
Traditional way was use a long screw driver - touch one end to your ear, the other
to places accessible in engine.
I would also try and hold down with your hand, different parts of valve cover.
If it is a worn out timing chain tensioner , you can check by removing
valve cover. see vid at bottom.
Depending on which chain tensioner is chattering, you may not have to tear it all apart.
There are two.
Check around Youtube for videos showing changing timing chain tensioner without
removing everything and how to visually check it with valve cover removed.
I know there is a removable two bolt chain tensioner on left front side when you face engine.
There is a youtube channel called toyota maintenance. See vid called
Toyota Tacoma Humming Sound in Front

Also there is good vid regarding installing timing chain
tensioner;
https://www.youtube.com/watch?v=lJ812DijbNw
That is all !