Fan hitting duct shroud - ticking bad

[kach22i]

I was out of town for three weeks, car started up and I drove it for a couple of hours with no problems. The next morning it starts right up, but I hear this faint ticking noise, I shut down and check the fan belt tension - it's fine. I start it back up the ticking is even louder. I shut it down and look for debris in the fan duct and lose items which could be vibrating. I start it back up and take a video, it's rapidly getting noisier at an alarming rate.

As you can see from the pictures there is one spot which the fan may be hitting. I have no idea how one spot could just rise up and deform a perfect circle.

I did replace the alternator last year, could something have come lose?

What's wrong (root cause), and how do I fix it?







Video at very low idle, not warmed up yet.
http://s184.photobucket.com/albums/x295/kach22i/Porsche/?action=view&current=Imgp6096.flv

Video with revs, ticking increases.
http://s184.photobucket.com/albums/x295/kach22i/Porsche/?action=view&current=Imgp6098.flv

[Won]

Check the nuts holding the alternator on to the fan housing.

[1982911SCTarga]

If you've ever studied the magnesium fan housing, it almost seem like magnesium corrodes in a funny way, like almost inside-out. So you sometimes see these raised areas. Or your housing may be cracking or something. Maybe it's time to upgrade from your five-bladed fan.

Brian

[kach22i]

Originally Posted by Won

Check the nuts holding the alternator on to the fan housing.

Dang, I was afraid someone would say this, I bet it's this.

The strap bolt over the fan housing was not lose to the touch, nor did I see any cracks in the shroud.

Money is very tight, the fan upgrade will have to wait.

[GothingNC]

Was the belt over tightened causing the alternator bearing to fail early?

[3.2 CAB]

It looks like it could be the bearings in the alternator might have gone bad, giving too much play in the rotating fan assembly. Have you taken the belt off and rotated the fan by hand to see what it does. It may have a wobble in it now?? Good luck!! Tony.

[rnln]

check fan bearing?

[kach22i]

Thanks for more clues.

I left work early and picked up some metal polish for the fan and paint for the pulley.

I started the car and moved it into position to work on and guess what? No more ticking sound. I shut it down and restarted, still no ticking sound.

I guess I should open it up and see what's going on. I don't want to be 50 miles from the most of my tools on the side of the road trying to sort this out.

Here I go again.