Alternator wine

[BamaTB]

So I changed the thermostat on the old TB and with the new belt I'm getting a grinding/whining noise from my truck now. Do any of u guys know what i would need to change out those bearings and or the pulley? And anything on the idler pulley? I dont know if i can just use standard tools or what. Thanks for any and a input.

Logan

[Moots1288]

So I changed the thermostat on the old TB and with the new belt I'm getting a grinding/whining noise from my truck now. Do any of u guys know what i would need to change out those bearings and or the pulley? And anything on the idler pulley? I dont know if i can just use standard tools or what. Thanks for any and a input.

You shouldn't have the title alternator whine because most likely it is not. I'd start with the idler pulley and the tensioner pulley, two easy swaps. Could be the bearings in those two, and they bolt just require a 15mm socket. Then you can look at the ac compressor bearing.
Logan

[Moots1288]

My reply was weird sorry about that stupid phone. You can take the belt off and spin each pulley and see if you hear grinding.

Sent from my SPH-L720 using Tapatalk

[BC backroader]

I had the same thing a couple of weeks ago. With the hood up, it seemed to be coming from the alt, but once the belt was off, it was obviously the idler pulley, as it had a terrible grinding noise when I trieed to spin it. It's a cheap part, about $40, and can save you a ton of grief if you get it fixed before it fails, as the belt can do a lot of damage if it flies off the seized pulley.

[BamaTB]

Thanks for the input, that snapped belt scenario is exactly what I am thinking on haha. Anyways, thanks guys. Also, even after putting on the new thermostat (last was stuck open) I'm still getting code p0128 or whatever. When I hit highway speed my temp gauge begins to drop quickly but erratically. (Down then wobbles back up then down again) anyone know what would cause this?

[v7guy]

bad replacement thermostat, bad temp sender.

[BC backroader]

I agree with v7guy, but will add bad water pump to the list. Worn or broken blades in the pump could give you erratic water flow, and possibly the noise you're hearing, too. Check it out when you've got the belt off.