Car Doctor Q&A: More Garden Shed Automotive Diagnostic Tools!

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The other day, Car Doctor John Paul suggested that a leafblower was a good tool for tracking down air leaks. Today, he heads back to the shed to see what other implements he can use to diagnose problems.

Q. I recently replaced the alternator in my car because of a noise I was sure was coming from a bearing in the alternator. After I installed the new alternator the noise was still there. I then found out the noise was coming from the belt tensioner. I replaced that and the noise is gone.

Here is my question: I diagnosed the problem with a “mechanic’s” stethoscope that I used for years to find noises. I was convinced that the noise was a bad bearing, any idea what happened?

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A. I also have a mechanic’s stethoscope, medical stethoscope and a electronic stethoscope and over the years they have all worked but have also been the source of some confusion.

One of my favorite tools is a three foot long piece of garden hose. A simple/cheap tool–hold one end to your ear and use the other to listen for noises.

I like a hose for two reasons: First, the noise dissipates quickly when you are not right on top of the faulty component. Second, unlike a mechanic’s stethoscope, a rubber hose doesn’t conduct electricity. Nearly every technician that I know of when probing around a cylinder-head with a stethoscope has gotten a shock, something that doesn’t happen with a piece of garden hose.