How to diagnose squeaks, creaks, and squeals

If you want to be seen as a Car Doctor, you have to look like one. And owning (and wearing) an automotive stethoscope is just the right way to do that. It's also the perfect accessory for your Car Doctor toolbox. A stethoscope is the first tool a pro uses to narrow down the source of humming, grinding, buzzing, squealing, or a screaming bearing. Old-timers use a old garden hose. But a professional stethoscope is so inexpensive and can do so much more, that you’re really wasting your time with a hose.

Start by attaching the amplifier attachment on this Lisle automotive stethoscope. It has a bell shaped end that picks up and amplifies sound waves. Pop the hood of your car and move it around until the suspect sound gets louder. The amplifier will pinpoint exactly where the sound is coming from.

Squeaking belts are usually the sign of a worn belt, a worn idler bearing, a worn pulley, or a mis-aligned pulley. Use the stethoscope to rule each one of the possibilities in or out. However, DO NOT EVER use belt dressing to solve the problem. Belt dressing is an aerosol spray that coats the belt with a sticky substance. The noise will go away almost instantly. But don't fool yourself into thinking you've solved the problem. That sticky stuff will attract all the road grit, sand, salt, and dust that gets kicked up from under your car. It will stick to the belt and pulley and act like sandpaper, grinding away at all the components. Before you know it, that "new" belt you just installed will be ready for the garbage can. The idler rollers and pulleys will be so polished from the grit that you'll be able to see your smiling face in the shine. But when you discover that you'll have to replace all those components, your smile will quickly disappear.

If you have a metallic screeching sound, switch to the metal probe attachment. Touch it to the NON-ROTATING part of idler rollers, power steering pump, alternator, A/C compressor, etc. You’ll definitely be able to detect which bearing is going bad by comparing the bearing noises from one component to another. Got an engine noise that’s driving you crazy? Use the probe for that too. The probe can pinpoint a bad rocker arm simply by moving it along the valve cover. You’ll look like a Doctor and you’ll diagnose like a Doctor. Now, if only your W-2 matched that of that Doctor down the street who drives a Lexus. The Lisle 52750 stethoscope is available from: http://www.tooldiscounter.com/ItemDisplay.cfm?lookup=LIS52750 Price of $15.42 includes the probe AND the amplifier. ©, Rick Muscoplat

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