Engine "Woo Woo" Noise

[tirwin]

Hey, OsoMoore -

I was just looking at your picture and thinking about what might cause that significantly uneven wear. I wonder if your fan has been balanced properly? When Mark Motshagen refinished my fan he balanced it as part of his normal process. The other possibility is that it had too much tension on it (incorrect shims?) or the fan was improperly seated (not even) on the alternator. Just something to think about as you put it back together.

[OsoMoore]

Tirwin, it is possible that the fan housing itself was not properly seated, and might have been a little tilted under the strap. It always seemed a tad off and didn't quite match up with the shroud bolts.

I thought that I might have had my belt a tad loose, if anything. But over-loose seemed safer than over-tight. It would squeal once at startup from time to time.

I will check alignment very carefully when I reassemble.

[Westy]

I wish I would have found this thread a few days ago. My alternator bearing went out and the wife says she hears a funny noise. Kind of like a woo woo. The alt was throwing up to 16v and the fuel pump was in jet mode. Lots of tick tick in your video, so it's hard to say if it's the exact same noise, but sure seems similar.

[OsoMoore]

Westy, the voltage spike is very dangerous. If you are getting voltage that high, you should probably stop using it totally until it (and probably the voltage regulator) get fixed or something else in the car could fry.

[Westy]

Thanx OSO. I took it in and am now the proud owner of a new alternator!! Lately, I'm the proud owner of a lot of 'new' things

[OsoMoore]

Are there any good tricks to getting that 7mm bolt that has no clearance for my normal wrenches?

[timmy2]

1/4" drive thin wall deep socket usually works. snap-on Mac or craftsman ???

[wwest]

Looks like slip rings and brushes have a different plus/minis wear rate.

Much like spark plugs I suppose.

5 minutes 20 seconds in...

https://www.youtube.com/watch?v=f56-26I6idc




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

[OsoMoore]

I found a local shop (recommended by another shop I trust) that does alternator rebuilds. Quoted 40-65 dollars. Going to drop it off tonight.

I figure I can muddle through it myself, buying new tools and waiting for parts. Or I can get it done by someone with the right know-how. Right now life is too busy and I really want the car back on the road.

Once I get the box from Ingo and this rebuilt, I should be good to go. Maybe by this weekend???

[wwest]

Originally Posted by OsoMoore

I found a local shop (recommended by another shop I trust) that does alternator rebuilds. Quoted 40-65 dollars. Going to drop it off tonight.

I figure I can muddle through it myself, buying new tools and waiting for parts. Or I can get it done by someone with the right know-how. Right now life is too busy and I really want the car back on the road.

Once I get the box from Ingo and this rebuilt, I should be good to go. Maybe by this weekend???

That price likely doesn't include a stator rewind, which they may suggest once they get a good looksee...

[wwest]

At this point I am again concerned that the alternator was the source of the tach jumping and subsequent rev limit FP shutoff/latch all along.

Have your shop closely inspect the stator windings, insulator, standoffs, etc, for possible intermittent shorts. Mine used "paper" insulation between the stator windings and the metal standoff supports, that "paper" insulation was burned to a crisp in several places.

Also, and intermittently shorted, or even an intermittently open diode might be a problem.

An aspect of my symptoms was that hitting a moderate bump/pothole in the road seemed to "trigger" a fuel pump shutoff.

In the end it was my theory that an intermittent short inside the alternator was generating a huge current flow spike and the resultant RFI/EMI was being coupled into the dizzy magnetic pickup coil.

I changed out the alternator for one FEDXed from PP but by that time the CDI was toast (mostly) due to the long period of operating at 15-16 volts. Car would run for... then shutdown but could be quickly restarted via cooling the CDI with garden hose spray.

[wwest]

One more...

A shorted bridge diode, 1 of 6, will definitely result in overheating the alternator, and at the same time overcharge the battery. With one phase shorted the VR will "pump up" the rotor current to get the proper average alternator voltage output. That would mean that the PEAK voltage of the remaining 2 phases must be unusually high.. >15 volts.

[OsoMoore]

The bouncing tach went away after the dizzy work + new coil.

The alternator is now being worked on, should be ready for me by the weekend. The guy at the shop seemed a little amused that I brought it to him in pieces. After getting started on it myself, I ran out of time and specialty tools. Hopefully he doesn't hold it against me price-wise.

Depending on Ingo's ship time, I may have both pieces by the weekend. Fingers crossed!