belt squeeks

[fdb70]

Everytime i start my car(when the engine is cold), I hear a loud squeek for at least 6 sec. I assume it comes from the belt. Also, when I turn on the headlights at night, my battery light goes on. Does this mean that my alternator belt is loose & needs tightening or its time to replace the alternator/battery. If so, can you please give advise on the procedure.

Thanks,
Fdb

[Dave's 944]

Definatly sounds like a belt needs to be tightened. Fortunatly the Porsche engineers where alot smarter than most american car manufactures and made it really easy to tighten the belts. Just get under the car and thiers a long pressure rod that goes between the alternator and the block. Lossen the locking bolts and then just turn the middle bar to tighten the belts. Beware of overtightening though it will where out the bearing in your alternator. Hope that helps

[cyclemike]

Remember when tightening this adjuster, you have to loosen the mounting bolts of the A/C compressor. If you don't, sooner or later(probably sooner) one of the eye-bolt ends will snap under the awkward lateral pressure. Trust me I know this first hand.

[olerebel]

How do you know how much to tighten it?

[EMBPilot]

5-4mm of belt deflection across the span.

[Hoss Ghoul]

I wouldn't assume it is a belt or that it needs tightening.

I have a similar squeak/squeal(I would describe it) and my independent Porsche mechanic-30+ years of experience-told me it was the alternator itself(and normal)...not saying that is your issue, but I wouldn't automatically assume it is a belt. Mechanic recommended doing nothing.

EDIT: I should say that if you have a battery light coming on there is obviously an issue, just want you to explore all the options.

[legion]

I had my alternator rebuilt last spring.

I put in a new alternator belt and a new water pump belt. It ran fine all summer, but when the temperature got below 50º, it would squeal like a stuck pig for 3-4 seconds on startup.

I'm not concerned.

[hpaulb]

Could be both or either. Precaution. Doing any work, I always take off the alternator and take it in to an alternator/generator shop. Not just Pep boys. These shops have always tested it for free and if it needs work, they do just whats needed. These are bosch. Lots of parts end experience around. They'll test it under load for more than output. A worn bearing will cause this and it's cheap to replace.