HELP! - Wierd Noise and I'm nervous

Rot 911 · 08-26-2002, 07:44 AM

'86 Carrera. This noise is tough to describe, but I hope someone has an idea for me. This morning when I started the car, for just a few seconds I had a noise that sounded like a wire or stick clipping the edge of the fan blades. Not the chain dragged across the trash can sound of doom of a collapsed tensioner, but more like an stick or wire hanging in front of the fan and intermittently being sucked in and clipping the edge of the fan blades. Only lasted 3-4 seconds then gone. No noise after that. After I had been at work a couple of hours I went out and started the car. Same sound again. Before I could open the engine lid up, the sound was gone. I can't find anything hanging loose around the fan. Is it possible to have a tensioner lose pressure and partially collapse and then repressurize on start up? The whole thing is making me nervous!

JDaniel · JDaniel's Garage

Starter problems?

Have someone else start the car, while you stand in back with the lid open.

Rot 911 · 08-26-2002, 09:49 AM

Quote:

Originally posted by JDaniel
Starter problems?

Have someone else start the car, while you stand in back with the lid open.

I did that and it sounds deep inside the fan housing. It is definitely a metallic "ping" noise and only last a couple of seconds. Is not consistent with the turning of the fan. Just "ping". . . "ping, ping" . . ."ping" I can duplicate the noise with the car off by lightly tapping one of the fan blades with the tip of my key. I hate the obscure noises!

Jim Sims · 08-26-2002, 10:39 AM

Based on information posted; two conjectures: (1) a piece of debris has been inducted into the fan and is hung up where it contacts the fan until the air flow pushes it out of the way, (2) the fan system has developed "play" of some sort that is relieved once the fan is running and there is an axial reaction thrust on the fan; this play is causing the fan blades to contact something upon start up. IMO the likely causes of the "play" are: alternator bearings or bearing retainers beginning to fail, followed by a cracked fan shroud, followed by loose alternator nut or incorrect installation of pulley shims and outer pulley half, followed by incorrect spacer between fan and alternator. Has anyone been in there lately? How old is your alternator? It's probably time to get in there and inspect things. Cheers, Jim

Rot 911 · 08-26-2002, 11:20 AM

Jim, what you are saying about the alternator bearings makes sense. I'm sure the alternator is the original. I've got all the receipts for the car from day one (thank you previous owner!) and don't see one for an alternator. I'll check things out tonight!

Rot 911 · 08-26-2002, 05:11 PM

Jim you guessed it right. Took off the fan belt and I can feel play in the alternator shaft when I grab opposite fan blades and wiggle them. Also can spin the fan by hand and see and listen to it scrape on the housing. Guess it is a new alternator for me (and yes, my money goes to Pelican!)

Sean Hamilton · Sean Hamilton's Garage

Kurt - see the below thread :-

Fan Wabble - 1980 SC

I had a similar problem, and it was

Guru Jim (as usual) that helped diagnose this too. Note what Moses and Jim say about "Have the internal parts checked too". Mine needed a total rebuild - internal electrics and front & rear bearings. But I'm happy now and learnt a lot along the way

P.S. I see you're into the pommy stuff too - I've got a TR4. Sure makes me appreciates how wonderful a Porsche is. Still, there's no....(edit).... they shouldn't be compared.