Cody

When I start the car, I hear it.

Its a high pitched noise......like a small bell ringing. When I rev, it gets a little higher pitched.

This is a 12a motor. I have just the alternator belt still attached, and the original fan clutch, which seems to be in working order.

The belt isn't slipping, and it's not a squeal. It sounds like a tiny glass bell ringing.

Anyone recognize this sound?

zookeeper

Alternator getting ready to give up the ghost. That's what mine sounded like before the bushings seized. Drove me crazy trying to figure it out. It's almost above the range of hearing, a "tinkling" sound. After the alternator froze and I changed it, the sound was gone.

thorin

i bet it is the belts.

when my belts wore out, they made that noise. it was wierd, because it wasnt the sqealing noise youd expect

AdrenalifeRX7

yep mine did the same thing when the alternator bearings seized up. after the bell stops ringing your belt will start frying it self on the pulley.

NanaimoRx-7

Hey I think I might have that too. It's really hard to locate, it almost sounds like it's coming from the flywheel area. But when I walk to the other side of the car it seems to be coming from somewhere completly different. I might take a closer listen to the alt, I have a friend who is about to upgrade the alt on his FC, when he does I'll give his a go and see what happens. I can't think of a better excuse to upgrade to an 80 amp alt.

NanaimoRx-7

Another thing I just thought of; while the sound does appear to be RPM dependant it can also spin down in pitch when I start to cruise at a constant RPM. I was thinking about recording it and posting, but it would be damn near impossible to hear.

Cody

Ahh. Alternator does make sense. I know its not the belt, because I have a brand new one on there, and it's not a belt squeel.

Is the AMPS guage supposed to read exactly 12? Mine always seems to read like 15.

AdrenalifeRX7

A healthy alternator puts out about 14-15 volts.

Matty's first 1st Gen

I think 15 is a little high, Optimum i believe is 13.8V

Keaponlaffen

Right on the money.

but 13-14 is acceptable.

Cody

Well, whatever it puts out, its always over 12.

So, if I took this alternator out, to have it tested, would it read faulty, at like AutoZone or something?

zookeeper

Probably not. The noise you're hearing is worn bearings/bushings, whatever. They may be able to tell you how worn, though, just by how much freeplay is in the shaft.

Is there an alternator/starter motor rebuilder near you? They can check it out and rebuild it if necessary for about half the cost of a new one.