Common starter motor problems

Introduction to starter motor problems

Understanding the role of the starter motor in your car's starting system is key. The starter motor plays an important part in engaging the engine's flywheel, allowing your engine to start. When you have starter motor problems, it can be frustrating and inconvenient – especially when you're in a rush to get to work or pick up your children. Knowing the common starter motor symptoms and how to troubleshoot them can save you time and money. 

How do starter motors work?

Starter motors play a crucial role in getting your car engine running. When you turn the ignition key, the starter motor receives electrical power from the battery. This power activates the motor, which then turns a small gear.

This small gear engages with the engine's flywheel, turning it to start the engine. Once the engine is running, the starter motor disengages and turns off. It's a simple yet essential process that kickstarts your journey every time you drive.

Common symptoms of starter motor problems

Engine won't start

A faulty starter motor can stop your car engine from starting. If you turn the key and nothing happens, or if you hear a clicking noise, the starter motor might be the issue. This can leave you stranded. The engine relies on the starter motor to crank and begin running, so when the starter fails, the engine will stay off.

Clicking noise

If you hear a clicking noise, this usually means that the starter motor is trying to engage but can’t turn the engine. The sound you hear is the starter solenoid trying to engage the starter motor, but there's not enough power to turn the engine over. This can be due to:

• A weak battery
• Poor electrical connections
• Worn out starter motor components

Starter motor doesn't turn

There are several reasons why the starter motor might fail to turn the engine. These include:

• Electrical issues – Problems with the wiring, relays, or connections can interrupt the power flow to the starter motor.
• Faulty solenoid – The solenoid, which transmits electrical current from the battery to the starter motor, can fail, stopping the motor from turning.
• Worn out components – Over time, the internal parts of the starter motor can wear out, leading to failure. This includes the brushes, bearings, and armature.

Smell of smoke

If you smell smoke or a burning odour when trying to start your car, it could mean electrical issues in the starter motor. This can happen if the motor is overheating because of excessive cranking attempts or if there is a short circuit within the motor.

Electrical faults can cause wires to overheat and insulation to burn, producing a noticeable smell. If you encounter this issue, it's important to stop trying to start the engine and seek professional help immediately to prevent further damage.

Diagnosing starter motor problems

It's best to have a professional mechanic check the battery and connections, test the starter relay and solenoid, and inspect the drive gear and ring gear for wear or damage. A mechanic will use specialised tools to diagnose and fix the problem accurately. 

Potential causes of starter motor problems

A dead battery can often appear to be a starter motor issue because both result in the engine not starting. If you turn the key and hear nothing or just a clicking sound, it might be due to a flat battery rather than a faulty starter motor.

Oil leaks can also affect the starter motor's performance. When engine oil leaks onto the starter motor, it can lead to failure by contaminating its internal components. Electrical system failures are another common problem that impacts the starter motor.

Other issues that can prevent the starter motor from receiving the necessary power to function properly include:

• Corroded connections
• Faulty wiring
• Bad ignition switch

Solutions and repairs

Jump starting a vehicle can be a quick fix for starter motor issues, here’s when and how to safely jump start your vehicle:

When to jump start: If you turn the key and hear a clicking noise or no sound at all, and you suspect the battery is the issue, jump starting might help.

How to jump start:

1. Park both vehicles – Position the vehicle with the good battery close to the vehicle with the dead battery, but don’t let them touch.
2. Connect jumper cables – Attach the red (positive) cable to the positive terminal of the dead battery, and then to the positive terminal of the good battery. Attach the black (negative) cable to the negative terminal of the good battery, and then to an unpainted metal surface on the vehicle with the dead battery.
3. Start the assisting vehicle – Let it run for a few minutes.
4. Start the disabled vehicle – Turn the key and see if the engine starts.
5. Remove cables – Remove the jumper cables in reverse order.

For more detailed instructions, check out how to jump start your vehicle.

Look at our advice on how to jump start a car. But make sure you read the instructions in your handbook and follow those if they're different to our steps.

Replacing the starter motor

Sometimes, the starter motor needs to be replaced. Only a professional mechanic should attempt to do this – they’ll look for the following before carrying out the procedure:

• Symptoms Indicating Replacement – Persistent clicking noise, grinding noise, intermittent starting issues, or no response at all when turning the key.