Torque Shop: Car starter failure
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Slow start: A sluggish groaning sound when firing up the engine is one of the signs that the starter motor may be failing.
PHOTO ILLUSTRATION: UNSPLASH
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How do I know if the car’s starter is about to fail?
The starter is basically an electric motor that provides torque to the flywheel to turn the engine. In the conventional starter (as opposed to integrated starter generators in hybrid vehicles), a pinion gear on the motor shaft engages with the flywheel just as the ignition is switched to start.
No larger than a loaf of bread, the starter motor is powerful enough to spin the engine to about 300rpm, which is needed to fire up the engine.
One of the most common tell-tale signs of a failing starter is slow cranking when the ignition is selected to start. A weak motor will not have enough power to spin the engine fast enough to ignite and continue running on its own.
This will be obvious from the rather sluggish groan as the engine turns over much slower than usual. You may even face a situation where the motor simply refuses to turn. That is when you will need to call a tow truck.
These circumstances do not always mean that the problem is a dead starter motor. A proper diagnosis needs to be conducted before purchasing a replacement.
Other electrical faults can cause similar symptoms as a weak starter motor. For example, the main cable that connects the battery and starter relay, or even the ignition switch, could be faulty.
The high-current main cable can deteriorate over time. So can the power relay at the starter motor which functions as the switch to connect the 12-volt power supply to the motor every time the starter switch is activated. Unfortunately, there are no obvious means to determine the health of either the cable or relay.
