94 GT 5.0HO Idle Noise

[Mrlilwheeler]

94 302 5.0HO Idle Noise (YouTube Link)
Noise cancels out after 800 RPMS.
At 10’, idle rests around 650-700.
New Parts:
Idle Pulley
Serpentine Belt
Tensioner assembly
Water pump
Smog Bypass
Alternator
10’ Ignition Timing
Plugs
Wires
Coil pack

 

[General karthief]

Describe the sound or post a recording

 

[Mrlilwheeler]

Describe the sound or post a recording

There’s a blue video link at the very top. Thank you for the reply tho.

 

[Mrlilwheeler]

Sounds like the alternator bearing, in my opinion. It’s fairly new, but could be spun out from stress, when I bypassed the smog pump. I was forced to run a wrong size belt, due to a frozen idle pulley.

 

[General karthief]

Does the noise go away when you pull the belt

 

[Mrlilwheeler]

Does the noise go away when you pull the belt

I will give that a try in the AM.

 

[General karthief]

I'm with ya on the alternator making the noise

 

[jozsefsz]

Could also be the tensioner clicking when it bottoms out, if the belt's too long. From the video I agree with the alternator theory, but it's hard to tell where the noise is originating in 2D. I'd suggest a length of heater-hose held up to your ear and move it around the accessories (don't get it caught in the belt) until you pinpoint the location. You're guaranteed to look stupid while doing it, but it works very well.

 

[02 281 GT]

It almost sounds like electrical arcing inside the alternator.