I have a quirky problem and I'm not entirely convinced it's the alternator. I would greatly appreciate some insight and perspective. For the past several months when I start my 2001 996 C4 I would hear a combination of squealing and whirring, almost to the tune of a cat getting dragged around the serpentine belt through the pulleys. A general gentle grumbling shake would occur simultaneously. One curious day I noticed the voltage spike to about 17 volts so I shut the car down not before some obvious damage was done. The LCD on the climate control system cracked the battery swelled and needed replacement and then the car seems to run on battery power. I tested the output of the alternator as best I could, and wasn't convinced it was not putting out enough voltage.

The question is what is the chance the 80,000 mile serpentine belt is slipping on the alternator which in turn is not charging the system or is the alternator shot too?

Either way I am going to replace the serp belt, pulleys and tensioner. Any recommendations on anything else, which belt to get (brand), pulleys (upgrade to 997's) and best of all, where to get this? I've searched online and am, like many confused as to where to go.

Thanks again in advance!

All the best,

Shawn

 

To buy parts, suncoast or sunset porsche (same company)
Sorry, but your alternator is toast. but start with the belt. 5 minute job...

 

Shawn,
I had the same squeak and vibration last year. Replaced all the pulleys, serpentine belt, and power steering pump thinging that it would take care of it. But it didn't. Also noticed when I turned on the A/C it would be more noticeable, but my mechanic couldn't find anything wrong with it. Then he discovered it was the bearing on the alternator making the noise. When I turned on the A/C it put enough tension on the alternator to make it squeak and vibrate. He replaced the alternator and all is quiet now.
Hope this helps.