Serpentine Belt squeals – Ford
Serpentine Belt squeals on 1999 Ford Taurus with the 3.0L overhead valve engine, belt dressing doesn’t help.
Belt dressing sprays a sticky layer of goop onto the belt and that stops the belt slip, but it’s only a temporary fix. It never corrects the underlying problem. Worse yet, the sticky spray picks up road grit and literally grinds up the pulleys, making the problem even worse.
Start by replacing the belt. If it still slips, the problem can only be caused by a component that’s out of alignment or a worn idler roller bearing. If you haven’t replaced any major components lately, like an alternator, power steering pump, or air conditioning compressor, then head right for the idler rollers.
To find the culprit, invest in an automotive stethoscope (about $12 at an auto parts store). Remove the probe from the end of the tubing and start the engine. Move the tube around the belt area to home in on the source of the noise. When you locate the noise, confirm it by re-installing the probe and touching it to the non-rotating bolt in the center of the idler roller. Compare the noise to another idler roller. The bad bearing noise will stand out like a sore thumb. Replace the worn idler roller and your squeal will disappear.
If you have replaced a component, go back and check the alignment to make sure it’s installed properly.
© 2012 Rick Muscoplat