19th May, 2021 in Transport & Industry

The listening stick: The car mechanic’s best friend

By Brian Cunningham

When a modern car goes into the garage with an engine misfire or warning light glowing on the dashboard, the technician will plug in a diagnostic computer. This will display one or more fault-codes which identify the problem and advise which component needs to be replaced; often a plug-in piece of sealed unit, black box technology.

Back in the 1970s and ‘80s, when I was a car mechanic, diagnosis and repair work was very different. With a screwdriver, a spark-plug socket, a standard set of spanners and a decent hammer, I could keep just about any car on the road. Add a set of feeler blades, and a 12-volt test lamp and I could carry out a full engine service and tune-up, including adjusting the tappets, contact-breaker points gap, spark plug gaps, ignition timing and carburettor fuel/air settings! Much of the tuning work was carried out by sight and sound and feel. If the engine idle speed should be between 800 and 1000 rpm, I could hear when it sounded right and a half-turn on the fuel mixture adjustment screw would have the engine purring like the cat that got the cream.

Plus, I always had my ‘listening stick’, the most important tool in my box. It was a very long screwdriver with a wooden handle, an ancient piece of carpenter’s equipment, and I would place the tip of the blade against various components and hold the handle to my ear to hear what was going on inside a running engine. The mechanic’s listening stick worked exactly like a doctor’s stethoscope, to hear what was going on inside the patient. It was ideal for identifying the source of worn-out bearings, say in an alternator or water pump, and I often correctly diagnosed a worn camshaft lobe or broken valve spring by careful probing with my listening stick.

Every mechanic had a listening stick, and it was a highly personal and jealously guarded piece of equipment. No two listening sticks were ever the same. I worked next to a guy who used an old length of copper plumbing pipe and I knew a mechanic who swore by his foot-long piece of bamboo with a plastic funnel inserted at the listening end.

I wonder if, alongside his or her diagnostic computer, the modern-day mechanic also keeps a listening stick? I really hope they do!