Screeching Boxster

[Topless]

Start with the basics. Which model 98 (tip/5spd)? mileage? Recent service history? Was anything changed recently that was followed shortly by the screeching sound? Motor oil fresh with good color? Power steering fluid clean and topped off? The polyrib belt should be changed at 60k and 120k miles. Was this done?

You can remove the carpet and access panel behind the seats to get to the belt and pulleys. Give em a look. Release the belt tension and give each of the pulleys and accessories a spin. If one has a failed bearing you will know.