EMBPilot

Alright, it appeared out of the blue...

i believe it is an alternator bearing but i would like the experts to chime in.

porsche gods are not happy with me this wrenching season

also important to note, during pulley removal to diagnose:
the nut on the alternator shaft, is spinning on the alternator shaft freely without moving. the nut was torqued properly with a crows foot. ive never experienced anything like that before either, not sure what to do to get it off?

EMBPilot

alternator belt cut off. No more noise.

- shaft nut still stuck, spinning on the threads but not moving?
- not sure whats wrong with alternator?
- alternator was showing 12.3 volts at idle before we cut the belt off. no electrical issues.

let the record show, my car is now stuck at quads house in his garage, and quads car is stuck in my garage... wtf...

IXLR8

Was the crows foot 90 degrees to the head of the torque wrench and did you possibly confuse Nm and lbf.ft.?

IXLR8

Alternator bearing gone?

Cut the nut off using a Dremel. Keep grinding dust and metal contained. This is going to cost a bit.

If battery voltage was 12.3V at idle with no load, you are not charging. Should be 14V - 14.4V. I sit at 14.1V at idle. Charge the battery using a charger.

EMBPilot

yes it was 90 and im sure it was correct, i recall the value seeming pretty low as well and the wrench having the feeling of it being a lower value.

the only thing i can think of is to attempt to cut the nut off.
with another set of hands i may be able to get a flat head screw driver behind the nut and try turning it with some pressure behind it.

edit: just saw your second post alex, thanks.

once the alternator comes out i'll get it rebuilt locally. not sure what to do about the shaft situation. if the shaft is damaged or if the nut is stripped on the shaft.

pp000830

fan blades hitting shroud. Something out of alignment?

EMBPilot

not the fan cause once the alternator belt was cut the noise stopped so its the alternator. but the nut is stuck on the shaft...

the alternator + Fan and pulleys all together are now out of the car as a unit.

Quadcammer

what a terrible turn of events this was. Thing made noise like a rod was hanging from the case.

yeesh.

IXLR8

Long shot....but might the alternator bearings be so worn that the alternator rotor is making contact with the stator?

The noise stopped when the alternator belt was cut off. What does hand rotation of the alternator shaft feel like. Smooth? Any wobble?

IXLR8

Cost may not be worth it, but the shaft could be TIG welded up, turned on a lathe and new threads cut.

Quadcammer

thanks for your input alex. By hand things felt ok. I'm no pro on checking bearings. The noise was not present right at start up, it started about 2 seconds after the car was running.

no clue beyond that, I just work here

IXLR8

QC, even a bad bearing may feel good.

I checked a fan hub bearing that ran as smooth as a new bearing but was noisy in use and vibrated. Play was ever so slight as well, almost indetectable at the fan blade ends. As good as the bearing felt, the bearing was practically dry.

It'll be interesting to see what you find.

EMBPilot

Perhaps I should just give the entire assembly over to the shop (fan w alt) and tell them to install new fan hub bearing, rebuild alternator, fix nut goes w/o saying.

EMBPilot

Entire thing dropped off at P-Car Indy. Will report back.

MarkD

late to the thread... sorry
Best I can tell from the video, based on experience it sounded like fan contacting shroud assembly
Which means rear bearing in alternator

I realize yours is out of your hands now, but you would be able to see small marks on the shroud
And if you wiggle the front of the shaft very gently, feel movement in the rear bearing

With the alt belt removed, it very well could have let off enough tension on the alt shaft to avoid contact with the shroud.
I'm sure your shop will sort it out
Good luck!