Clanging noise around alternator

[explorerguy94]

I have a 93 EB explorer 4x4. Its making a clanging noise that sounds like its coming from the alternator and I can also hear a faint zapping surging sound. It gets louder and faster when giving it gas. It likes to cut off sometimes when idling a few minutes or sitting at a light or something. I took it to advance and autozone to get it tested and they said the battery and alternator was fine. The battery died a couple times when it was very cold. I have noticed my dash lights brighten up when driving and the battery light occasionally comes on but the gauge reads normal.

 

[nitro71]

Maybe you can get a stethescope at somewhere like Harbor Freight and pin point the the noise? If it is the alternator I'd replace it as it shouldn't be making noise.

 

[92exp4x4]

The regulater is probably on its way out. Unless you have a big load on the system your lights should not fade out. Do you have subs in your truck, or other big load on the battery?

While running at idle the voltage at the batt terminals should be about 13.8-14.5 volts. If not, then look for voltage drops. Check it at night too, you will see a spark in the dark.

 

[shaggymane]

Yeah, what they said. Just because it's still putting out *proper* volts doesn't mean that the bearings aren't long for this world.
When your lights get real bright, they tend to burn out soon

 

[cogs]

keep us updated on the fix for this.

 

[explorerguy94]

The only thing I have is a radar detector, cb radio and police scanner. I gonna get a stethascope from a friend. He said its sounds like the tensioner or idler pully.

 

[explorerguy94]

I forgot to mention the check engine light is not on. The only lights that come on are check oil and rear antilock light and occasionally the battery light but it hasn't come on lately.

 

[92exp4x4]

The battery light can come on when over-charging as well as under-charging. I had one charging 19 volts at idle, if i revved the motor just a little, my meter would go out of limit on the 20 volt scale. It destroyed the battery and luckily nothing else. I'd say if it charges more then about 14.7 V, replace it.

 

[explorerguy94]

Its the bearings in my alternator and the belt tensioner was bad.

 

[cogs]

since yours is the same age as mine, my idler pulley broke apart, but started screaming before that (had trouble locating it, until it broke). you might check the center bolt on the pulley, that it's tight. (my belt tensioner fell apart awhile before that also).

 

[explorerguy94]

I replaced the alternator with a junker and noise is gone. I replaced the belt tensioner but the one i got was for a 92 model cause they changed it sometime in 93 and it wasnt all the way down but off to the side so it wasnt putting tesion on my belt. It ran but there was alot of slack and my belt looked like it was gonna slip off so I got another belt and it was the same way. So I took it back to autozone and tried 3 different belts to get the size I needed. i bought the tensioner from advance but when they looked up 93 explorer it was the wrong part and I took it back and they looked up for a 92 model and it was right but I dont understand why it wasnt working for the right belt.