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lou's garage

How long should start-stop starters work for in new cars? The old type of starters should be good for approximately 2,000-2,500 cranks, and while waiting at red lights you can hear how starters crank around you.

Best regards, Roman K.

I’m not sure where you are coming up with those starter motor longevity numbers, but they do not seem accurate to me. I think multiplying your number by 10 would be a better starting place.

Regardless of that actual number, when considering vehicles with an auto start-stop system, they typically have modified starter motors compared to their regular counterparts.

With carbureted and early fuel-injected vehicles a couple of decades ago, the mechanical forces required to get those engines spinning was far greater, especially in colder temperatures. Think about how thick engine oil use to be. That thick oil really slowed things down. Starter motors had to be beefy and required generous amounts of electrical current to complete the task of spinning the engine up to the required starting speeds.

Contemporary vehicles have many advantages which make the job easier. Modern engines feature super thin oils and low-friction piston rings, reducing the mechanical force required to turn over the engine. Therefore, the ratio between the starter pinion gear and the transmission’s ring gear can be altered on start-stop-equipped vehicles to favour less wear on the starter. The start-stop starter’s electrical brushes, which were a common failure in the past, are made out of advanced carbon materials to also lengthen their wear out time. Additionally, the bearings in a regular starter motor are not actually bearings, but oil impregnated bushings. On start-stop-equipped vehicles those bushings are swapped for actual needle bearings.

Another place we see changes is in the engine-management system. Engineers have now taken into consideration the relationship of the way the engine spins and its ignition firing order. It’s complicated, but I’ll do my best to keep it simple.

Up until a short time ago, when an engine turned over, the computer, also known as the powertrain control module (PCM), had to hold off spark plug ignition until it could identify and locate the engine’s cylinder No. 1 timing mark. This was critical to getting the ignition timing right as all calculations were based off the PCM knowing exactly where each piston was in the timing cycle. The PCM could only make these necessary calculations after cylinder No. 1 was identified. Normal spark plug ignition would commence thereafter. The time required to identify cylinder No. 1 occurs in the blink of an eye to us humans, but is fairly lengthy in the digital world. If this waiting for cylinder No. 1 occurred at every set of red lights it would be an issue. Since start-stop vehicles came into our world, manufacturers had to come up with a way to immediately start the timing and ignition cycle to alleviate the waiting for cylinder No. 1. A modern engine can now commence the spark plug ignition cycle the moment the engine starts rotating, allowing for a much shorter turn-over time.

Start-stop systems are not going away and are being improved with every new model. Premature starter motor wear is slowly becoming a non-issue.

The reason they are not going away is because they reduce fuel consumption. According to Natural Resources Canada data, a start-stop-equipped vehicle will see a fuel reduction of four to 10 per cent. Or between $80 and $200 per year. During 10 years of use, this technology will see a reduction of between 610 and 3,540 kilograms of carbon dioxide per vehicle. While it may be annoying, this technology is making a difference. Now if we can only get people to stop idling their cars for 20 minutes in their driveways every cold morning.

Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail, placing “Lou’s Garage” in the subject line.

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