Is this Alternator noise normal?

[strikee]

Hi. I took my fan belt off as it was squealing and needs tightening.

I was checking for bearing play on the fan and it seems really good, no movement.

Spinning the fan I get the noise in the video, not sure if that's normal or not, just the brushes on the rotor arm??

From the service history its been rebuilt before, probably about 40k miles ago.

Gives a good charge.

Thoughts?

Tempted to put it back on, tighten belt and off I go. You might need to turn volume up....

https://www.youtube.com/watch?v=eJy7rcK3SQg

Thanks
Ed

[T77911S]

no

[Targalid]

This is not a normal sound. You need to diagnose the problem. First, look for any places where the fan may be touching the fan housing or perhaps some debris has been caught in the assembly. This sounds a lot like fan scraping to me. Perhaps your fan housing is overly tight which can deform the fan housing from being perfectly round. If that is ruled out, remove the alternator/fan assembly and check the alternator for faults. Either a bad alternator bearing or possibly brushes worn to the holders would be sources of this noise.

[DRACO A5OG]

+3, not normal

Could be just the vr worn down

Remove and post pic of brushes

[Alfasrule]

If it's a Bosch the regulator is bad and is easily changeable. Happens on ALFA's all the time. Got 4 spares 2 bolts and a plug done. It's part of the alternator. Unfortunately in the ALFA I have to take it out to repair it.

[strikee]

Which is the preferred VR I should be looking at? PP has a number of them.

Thank you.
Ed

[Targalid]

Don't buy parts until you have a diagnosis.

[strikee]

Alternator to be removed ce soir.

[DRACO A5OG]

Originally Posted by Targalid

Don't buy parts until you have a diagnosis.

^^^ +1, always.

[Brudock]

Originally Posted by strikee

Alternator to be removed ce soir.

Keep us posted. I discovered the exact same issue when I replaced my fan belt.

[theiceman]

that sounds like the bearings are beat and the fan is catching the shroud. if so an easy fix for an alt shop .

[strikee]

I took everything apart last night. An entertaining but rewarding job.

I am 100% sure the noise is the front bearing so the plan is to take it to an alt shop for rebuild. I was considering doing it myself as the VR is external. However I dont have the right tools to get the bearings off.

The front bearing is obviously worn as the fan has a big section missing so its off balance.

The VR 'looks' ok but the brushes are different heights, not sure why. I will take advice from A shop on replacement or not. I cant tell if the VR is made by a reputable company or just some cheap rubbish.

New fan needed. :-( In addition to the bit missing, it has several cracks and dings. Its in poor shape. The shroud is good.

[DRACO A5OG]

Nice Diagnosis, So bearings were noisy off the car as well? My brushes were allot worse.

[strikee]

The noise seemed to be coming from the front, and where the front bearing sits. I thought it was the VR brushes at first, but with the external VR removed, it made the same noise.

Are there any more brushes internal to the alternator? Sorry if thats a stupid question, but Im thinking as I have the external VR, the brushes are on that and not internal to the alt.???

The alternator spins creating a charge, the VR picks up that charge via those two brushes and distributes to battery etc.

Opposite to an electric motor where the brushes transfer the power to the coil to make it turn.

Never really thought of it that way before.

Homer Simpson noises.

[strikee]

How do I split the ALTERNATOR open? I have removed the through bolts, is there anything else?

Tks

[86 911 Targa]

Identify this sound...
^^^^^
Here you go.

Gerry

[sugarwood]

Fan for $369
Porsche 911- 11 Blade Alternator Fan - Aluminum: Engine Cooling &amp Fans Related Parts

[strikee]

Nice, a classic "Crownee".

I have looked through your thread and as much as I like DIY, I think it will be quicker for me to drop alternator off at local shop. I was considering doing it myself but path of least resistance is to shop it while I get on with cleaning everything else. One of my fan blades is also cracked. I am going to attempt to balance using a cheap motorcycle tyre balancer I have. Replacement cost of fan here is a lot, esp with shipping. I will advise how I go.

[strikee]

Thanks Sugar wood.

However with shipping, and currency conversion, that equates to nearly $500 of my hard earned ozzie dollars. Plus I will have to wait three weeks for it to arrive. There are some on evil bay for a few bucks cheaper. Im going to attempt a fan balance as per above. She'll be right.

[DRACO A5OG]

Make sure take your pulley half and nut with you, they may not have one to test the alternator after refurb. Tell them not to hammer the alternator out.