How do you stop a sqeaky serpentine belt on a 300 ZX Nissan Turbo?

use belt dressing

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NO, belt dressing is only temporary and will not solve your squeaky belt for good. Your belts are either worn out, (cracked and hardened), when mixed with cold weather/ condensation, will squeak, OR they are too loose. New belts tend to need "breaking in" about 3 sequences of tightening should do the trick (no less than 1/2" play for most vehicles).DO NOT OVERTIGHTEN, as you will over stress a bearing, or cam. Belt dressing is basically WD-40, and is a quick fix that works in an emergency for covering up embarassing moments in your car. waste of money.