What Is a Starter Motor?
FixMyCar discusses what a starter is, how it works and how to test it.
Book a starter motor repair nowEllie Dyer-Brown
Friday August 08 2025
3 min read
The starter motor is a small yet powerful electric motor that gets the engine going when you start the car. Learn how it works and more in this guide.
What is a starter motor?
The starter motor turns the engine over during ignition by providing lots of torque (rotational power), creating the airflow needed for fuel combustion.
Where is the starter motor?
You can usually find the starter motor towards the back of the engine, near the flywheel housing. This location makes sense if you think about it – after all, the starter motor is one of the first parts of the engine to be activated when you turn the key in the ignition.
You might have to remove the exhaust system or skid plates to access it, which can make a repair more expensive due to the labour involved.
How does a starter motor work?
When you turn the key in the ignition or press the start button, an electrical signal is sent to a magnetic switch (solenoid).
The switch sends the charge to the battery and then the starter.
The electrical current activates the starter motor and a system of gears called the Bendix/starter drive.
Then, the electrical charge engages the flywheel.
When the starter motor turns, it cranks the engine, initiating the combustion process.
Once the engine is running, the starter disengages.
How long does a starter motor last?
A starter motor will usually last the lifetime of a vehicle, between 100,000 and 150,000 miles. However, it depends on the car make and model, as well as the quality of the part.
A high-quality OEM starter will typically last longer than a budget aftermarket part.
Can a starter motor drain the battery?
The starter motor shouldn’t continuously drain your car’s battery because it only operates when the vehicle is first switched on. It should disengage in less than five seconds.
However, if there is a problem with the starter, it can sometimes continue running, which will eventually drain the battery, but not for a long time.
A battery that goes flat due to the starter motor probably had something wrong with it in the first place.
How do you test a starter motor?
You can test a starter motor for any problems using the following method.
Listen for a clicking sound when you start the ignition. Rapid clicking is one of the most common signs of a starter problem.
Check the battery. Car battery issues can cause a range of faults, so make sure everything is in working order.
Test sensors and connections. The starter motor relies on various wires and sensors that must function correctly for it to do its job.
Still unsure what’s wrong? We can help you find a trusted local garage to carry out a professional diagnosis.
How much does it cost for a new starter motor?
The average quote for a starter motor replacement on FixMyCar is £392.02. See how prices vary between different car makes and models in this guide.
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Ellie is FixMyCar's Content Manager. She has over three years of experience writing about cars and regularly collaborates with automotive experts to provide trustworthy advice for drivers that is easy understand. Her work has been featured in Yahoo! Finance, iNews, The Daily Express and The Sun. She has a BA in English literature and an MA in creative writing from Durham University. Outside of work, Ellie follows F1 and eagerly awaits Ferrari's next era of dominance in the sport. She drives a Suzuki Swift.