The starter motor is a crucial component for starting a car and is often one of the first parts to fail in older vehicles.
While it is a common source of issues, diagnosing a starter motor problem may not always be straightforward. This article provides guidance on how to diagnose starter motor issues and what steps can be taken to resolve them.
What Does the Starter Motor Do?
When the driver turns the ignition key, an electrical signal is sent to the starter motor, which helps crank the engine until it begins running on its own.
The starter motor draws electrical power from the battery to generate the torque necessary to turn the engine over. It is typically located near the bottom of the engine and consists of a powerful DC electric motor, a starter solenoid, and a gear assembly.
The starter solenoid engages the starter motor, which then turns the engine via the flywheel. In simple terms, without a functioning starter motor, the car won’t start.
Common Starter Motor Issues and What to Do
Dead Battery The battery that supplies electrical power to the starter motor can weaken over time or completely die, preventing the motor from turning the engine over. In such cases, the starter motor itself might be fine, but the battery needs to be recharged or replaced to resolve the issue.
Faulty Solenoid The starter solenoid is responsible for engaging the starter motor. A malfunctioning solenoid can affect the motor’s function.
If the starter motor continues to operate after the ignition is released, it could indicate an issue with the solenoid contacts. This problem should be addressed immediately, as continued operation could cause damage to the flywheel.
Worn-out Brushes Brushes are part of the starter motor and are responsible for conducting electricity to its internal components. Over time, these brushes can wear out, which can cause the motor to malfunction.
This wear leads to increased resistance between the brushes and the commutator, making it harder for the motor to crank the engine. Signs of this issue include grinding noises or dimming lights when starting the car.
Oil Soak The starter motor is located near the base of the engine, so it is susceptible to oil leaks. If the starter motor becomes soaked in oil, its lifespan can be significantly shortened. To prevent this, it’s crucial to address any engine leaks immediately and replace the starter if it becomes damaged due to oil exposure.
Freewheeling “Freewheeling” occurs when the starter motor is disengaged from the engine and fails to transfer power through the flywheel when trying to start the car. This can result in a whining noise, signaling that the engine isn’t starting. Freewheeling is usually caused by a faulty starter gear drive.
What to Check If the Car Won’t Start
If the starter motor is not engaging, here are some steps you can take:
- Check the battery: Ensure the battery is fully charged and provides enough voltage to power the starter motor. Use a multimeter to confirm that the voltage is at least 12.6V.
- Inspect battery connections: Verify that the battery terminals are securely connected and free of corrosion.
- Examine wiring: Check the wiring connections between the battery, starter, and solenoid. Ensure all connections are clean and tight.
- Test the solenoid: Use a multimeter to test the starter solenoid. If it’s malfunctioning, it may need replacement.
- Inspect the starter gear: Check the starter gear for any damage or wear. If it’s worn out, replacing it may be necessary.
These checks require familiarity with car components and electrical testing procedures.