A starter is the major component of a vehicle’s starting system. It does exactly what its name says, physically cranking the flywheel to start combustion. Once you turn the ignition key or push the start button, the starter’s pinion meets the flywheel attached to the crankshaft, allowing the starter motor to turn the engine.

Saying a starter, we usually mean an entire starter assembly that includes a starter motor, a solenoid, and a starter electrical circuit. A starter motor is the largest part of the assembly. Its job is to rotate the flywheel when you complete the ignition circuit. A solenoid is an electromagnet that engages the starter motor when you turn the ignition key, and disengage the motor once the engine starts running. Solenoid and starter motor operation is controlled by the engine computer or the ignition module that supplies power to the solenoid and the starter motor via the starter electrical circuit.

Designed for repeated use in different weather conditions, your starter can last the life of the vehicle. However, severe weather conditions and a lack of maintenance can shorten its service life and cause its premature failure. Fortunately, before your starter breaks down, you will notice a number of warning signs of a failing starter. Let’s check them one by one:

Your starter creates little force when cranking the engine

This is the most common sign of a failing starter motor or another related component. You should address this symptom once it appears to prevent more serious problems.

Your starter doesn’t crank the engine

If your starter doesn’t spin the flywheel when you push the start button or turn the ignition key, this means your starter motor, solenoid or another starting system component has failed or malfunctions. You may also hear clicking or clunking noises when the ignition key is in the start position. Plus, you may need a couple of tries to start the engine. If you fail, you’ll need to have your vehicle towed to a repair facility.

Occasional starting problems

Loose or worn-out wiring or a bad relay can cause intermittent starting problems. They can appear occasionally until the starter fails to operate one day. This warning sign should not be neglected as it may lead to further starter problems. You should have your vehicle diagnosed by a professional to prevent unplanned repairs in the nearest future.

Dimmed dashboard or interior light when starting the engine

If your dashboard lights get dimmed while the starter is cranking the engine, most likely you have a short circuit in the starter electrical system. This causes excessive power consumption within the electrical circuit, overloading the battery. In some cases, dimming lights can be accompanied by a chugging noise, which says about poor starter bearings.

Grinding noise when driving or starting the engine

This noise is an indicator of a mechanical problem either inside the starter or of a related starter component. The most common sources of this problem are worn-out or damaged starter gears and loose starter mounts. The starter pinion can also remain engaged when the engine is running. Whichever is the root of the problem, it must be addressed as soon as possible to prevent damage to the starter and the flywheel.

Your starter doesn’t crank the engine, yet produces whining or whirring sounds

This happens when the starter doesn’t engage the flywheel. As a result, the starter spins, but the engine doesn’t start. If so, the solenoid and the starter gears should be checked first. 

Your starter doesn’t stop cranking

Under normal conditions, your starter is disengaged once the engine has started or you release the start button. If this doesn’t happen, you might have problems within the electrical circuit. You should avoid driving a vehicle as it may cause damage to the starter and the flywheel.

Smoke or burning smell from under the hood

Your starter houses both mechanical and electrical parts. The mechanical ones are lubricated with grease, which can start burning if a short circuit occurs or the parts are getting overheated. If you notice smoke or smell coming from the starter, you should stop the engine immediately.

Engine oil inside the starter

Your starter is located deep inside the engine bay. If there are any oil leaks close to the starter, it may collect engine oil. Hot engine oil can quickly ruin the starter and cause a short circuit.

Starter troubleshooting and replacement

A starter is a complex device that should be properly diagnosed before any replacement or repair is done. In many cases a malfunctioning starter can be caused by a bad battery, improper operating charging system, wiring issues, or a bad ignition switch. That’s why you should check them first.

If there are any signs of oil inside the starter or on its housing, the source of the leaks must be found and the problem must be fixed before replacing the starter or its components. 

Depending on the symptoms you have, you may need to replace the entire starter assembly or just one of its components, for example, the relay or solenoid.