Bad alternator or some sort of pulley?

mechanic says alternator or water pump. i put a screwdriver to the alternator and my ear and it sounds really scratchy and crunchy. i touched my hand on the oil filter aswell and it vibrates with the sound, i’m really concerned. the noise comes and goes though some days it’s not as bad some days it’s as bad as this video
https://m.youtube.com/shorts/pMQXf2iFXuo
this is my video by the way^
also my truck has never died or not started, no battery light nothing. i’m thinking bearing maybe? hope it’s nothing too serious

 

I’d pull the belt off and spin the alt and WP by hand. They should both turn smoothly. If one or the other doesn’t, you’ve likely located the issue

 

okay thank you bro i’m gonna try this weekend, is water pump replacement hard

 

No, it’s not bad, just have to take the fan and belt off to get to it. There should be a good write up on here for the 4.0L on that replacement

 

It's pretty straight forward. Just a mess like any job that involves the cooling system.
Drain the coolant, Remove the Belt, Fan, Alternator, T-stat housing and Idler Pulleys.


Bolts A and B are big/little.
A = Little bolts
B = Big Bolts





Thermostat

 

thank you so much bro what water pump do you recommend? any good brands?

 

thank you sir

 

Aisin only. Aisin is the OEM pump.

 

Aisin is what I used and recommend

 

you know exactly what model for the 4.0L 2006 engine? there’s so many models when i search it up

 

71.99??

 

Go with the Aisin from Rockauto. The WPT 136 looks to be the correct one

 

water pumps don’t last forever. Nor do pulleys. You can replace those. Power steering pump is a maybe. That right there is most of it.

if the sound continues then you’ve ruled other things out to narrow it down.

can alternators go bad by now? Yes. Other brands by now it’s common to put new front bearing with special socket. That holds the pulley. Don’t know if that’s possible on the Tacoma. Hope it is.

you can also get the belt off pretty easily to spin things by hand and see if any are suspect.