1988 Ford Ranger replace alternator, new sound?

[SolusUmbra]

I replaced the alternator on my 1988 Ford Ranger 2.0L and now it sounds like a tea kettle. Wonder if anyone else can hear the whistle and know what it might be.
Link to my Reddit post that has a video https://www.reddit.com/r/MechanicAdvice/s/QL91hviZUA

 

[Rand]

well theoretically its the alternator? since it didnt do it before?

 

[Oillover]

Alternator or tensioner pulley are my guesses.

 

[ripcord]

Sounds like a bearing. Take the belt off and spin and rock back and forth everything that's spin-y that the belt goes around. If anything makes noise or has noticeable play, that's probably your issue. Could be an air conditioner clutch pulley or water pump bearing in addition to what's been mentioned.

 

[SolusUmbra]

Alternator or tensioner pulley are my guesses.

My alternator is my pulley

 

[SolusUmbra]

Sounds like a bearing. Take the belt off and spin and rock back and forth everything that's spin-y that the belt goes around. If anything makes noise or has noticeable play, that's probably your issue. Could be an air conditioner clutch pulley or water pump bearing in addition to what's been mentioned.

Truck doesn’t have ac, water pump was checked and was fine

 

[SolusUmbra]

Alternator or tensioner pulley are my guesses.

Mechanic checked my new alternator and said it was fine

 

[kschachn]

Post a video from under the hood, please.

 

[RooflessVW]

Get a stethoscope. Should find it pretty quickly.

 

[Oillover]

My alternator is my pulley

Sorry, I meant idler pulley
It looks like this:

Rock auto has a few options listed for that engine:

 

[ka9mnx]

Post a video from under the hood, please.

I cant hear it with all the other noise and distractions going on!

 

[JavierH19]

Why record from the cabin if you suspect it's the alternator? You can pull the throttle cable from under the hood in that older ranger. My old 2000 ranger had a cable throttle but I think it went away once they went to the mazda engine soon after. I wish electronic throttle bodies still had a mechanism so you can rev an engine from under the hood to check for issues only findable at higher speeds without needing a helper.

 

[zzyzzx]

New or rebuilt alternator?

 

[Auto tech]

Did anything get disconnected and causing vacuum leak?

 

[DCDG]

Close the hood put the volume up sound will go away

 

[SolusUmbra]

New or rebuilt alternator?

New

 

[SolusUmbra]

Did anything get disconnected and causing vacuum leak?

I don’t think so, only had to bolts and 2 plugs to remove

 

[SolusUmbra]

Why record from the cabin if you suspect it's the alternator? You can pull the throttle cable from under the hood in that older ranger. My old 2000 ranger had a cable throttle but I think it went away once they went to the mazda engine soon after. I wish electronic throttle bodies still had a mechanism so you can rev an engine from under the hood to check for issues only findable at higher speeds without needing a helper.

I was in a hurry to run an errand and just wanted to record the sound, I don’t suspect the alternator since my mechanic said it’s good, but it’s still bugging me on what it might be, it might just be a new sound I have to get use to. I feel a bit embarrassed to say I have no idea where the throttle body is. I know I’ve seen others do it when I was younger, but was too young to know I should have asked.

 

[JavierH19]

I was in a hurry to run an errand and just wanted to record the sound, I don’t suspect the alternator since my mechanic said it’s good, but it’s still bugging me on what it might be, it might just be a new sound I have to get use to. I feel a bit embarrassed to say I have no idea where the throttle body is. I know I’ve seen others do it when I was younger, but was too young to know I should have asked.

That's understandable. The throttle body Is where the tubing from the air filter box leads into with a mechanism at either side depending on the year. Found this video showing the motion.