Car Won’t Start? 8 Signs of a bad Starter Motor

A starter is one of the most important parts of the vehicle. It helps to quickly start the vehicle. When the starter motor goes bad, it produces different signs such as poor engine performance, hard engine starting, grinding noise, etc. This article explains the bad starter motor symptoms, causes, and how to replace it.

What is a Starter Motor?

A starter motor is an electric motor that is installed to initially turn over the engine and start it in a vehicle. It is also called a starting motor. This motor is usually installed near the transmission on the engine block and gets power from the car battery of your vehicle.

As you turn the ignition key, an electrical signal is delivered to the starter solenoid, which turns on the starter motor. When the starter motor starts, it rotates the flywheel of your engine, which in turn begins the combustion process and starts the engine.

The primary function of the starter is to initiate the rotation of the engine’s crankshaft, thereby starting the engine. Once the engine begins running, the starter motor disengages from the engine, allowing it to rely on the power generated through the combustion of the air/fuel mixture.

Sings of Bad Starter Motor

If your engine won’t start, it is one of the most common symptoms of a bad starter motor. However, a bad starter may also produce some other symptoms such as whirring noise, grinding noise, unpleasent smell while cranking, check engine light illumination, dim lights, weak battery, or smoke from the starter.

Let’s discuss these signs of a bad starter motor in detail:

1) Engine Won’t Start

When a starter motor begins to fail, the engine of your vehicle may not start. However, there are various causes for an engine not starting, like a dead battery, internal engine issues, a damaged solenoid, or a faulty ignition key.

2) Whirring Noise

If you notice a whirring sound while turning the ignition without any activity in the engine, this could be due to a malfunctioning pinion gear or a defective starter solenoid.

As you turn the ignition key, electric power should be supplied to the starter motor while simultaneously signaling the starter solenoid to activate. Upon receiving the signal, the solenoid engages a gear that extends and connects with the flywheel, causing the engine to rotate.

A whirring noise may occur if your starter solenoid doesn’t properly connect the gear or if there is an issue with the flywheel gear.

3) Clattering or Grinding Noise

Similarly to the whirring sound, a clattering or grinding sound from your starter may be produced when you turn the ignition switch.

If there’s an unusual noise coming from the starter and your engine doesn’t respond upon turning the ignition, it is one of the clear symptoms of a faulty starter motor.

This issue may also generate because of damaged internal parts like damaged bearings or axles. To pinpoint the problematic component within the starter, disassemble the starter for proper inspection.

4) Unpleasant Smell When Cranking

The starter of your vehicle is an electric motor equipped with a solenoid that functions as a “clutch.”

If you have prior experience with an electric motor, you might be aware that it may emit an unpleasant smell when nearing failure. The same principle relates to the starter motor.

A burnt odor while attempting to crank the engine, it’s highly likely that a component within the starter motor is defective.

However, the smell could also be produced by a poor connection in the power wires leading to the starter. Be sure to carefully examine the source of the smell before proceeding.

5) Smoke Rising from the Starter

A bad starter may not only produce an unpleasant smell, but it can also cause smoke to emanate from the starter. However, smoke can originate from various components of your engine, but if it appears only during the engine cranking process near the starter, there is a high likelihood that the smoke is being generated by the starter itself.

To confirm whether the smoke is indeed coming from the starter, ask a family member to observe the area around the starter as you attempt to crank the engine.

6) Starter Doesn’t Stop After Starting

After starting the engine and activating the Start button or releasing the ignition key, your starting circuit should deactivate. However, if you hear a persistent grinding noise coming from under the vehicle after the engine has started, it may indicate that the starting relay has become stuck.

In this situation, the relay continues to function as though you were still trying to start the vehicle, remaining in the “on” position. This can cause significant damage to both the entire starting system and the transmission flywheel.

7) Dim Lights and Weak Battery

Dashboard lights and operational headlights typically indicate that the vehicle has sufficient power for the starting system, even if the engine fails to start.

Starting an engine demands a significant amount of electrical power, which could lead to an issue with the vehicle’s battery. Attempt to start the engine using a starter pack or jump starter. If the engine turns over successfully, it indicates an issue with the battery.

8) Oil has Soaked the Starter

The starter is typically located on the passenger’s side of the engine (for RWD vehicles), just beneath the exhaust manifold. For FWD vehicles, it can be found on the driver’s side below the exhaust manifold or above the transmission.

In some cases, the starter may be situated under the intake manifold. If you open the hood and discover that your starter is soaked in engine oil, the faulty starter could be a consequence of another issue—an oil leak.

Regrettably, a small oil leak can gradually and sometimes imperceptibly escalate into a costly issue. To prevent starter issues arising from this situation, remain vigilant for any signs of oil leaks.

9) Check Engine Light

The engine control module (ECM) of your car constantly monitors the performance of the starter motor. When it monitors an issue with the starter motor, it may trigger the check engine light to inform the driver about the issue. 

Causes of a Bad Starter

Your starter motor may go bad due to one or more of the following causes:

• Loose wiring around the starter
• Corroded connections
• Corroded battery
• Worn-out starter parts
• Oil leaks
• Fuse problems

1) Loose wiring around the starter

Loose wiring connected to the starter is one of the most common causes of a faulty starter, as it is a vital component of your engine’s electrical system. This may result from work performed near the starter or vibrations produced by the engine.

2) Corroded Connections

Corrosion of contamination in the electrical circuit may pose a big issue in vehicles, particularly in humid conditions. Regular inspections can help prevent this issue and enable you to replace any necessary components to maintain the system’s functionality.

3) Corroded Battery

Your starter motor requires battery power to operate efficiently. A corroded or faulty battery may either fail to work or create additional problems within the starter system.

4) Worn-out Starter Parts

Since the starter consists of multiple parts, the wear and tear of any single part can lead to its failure.

5) Oil Leaks

The leakage of the engine oil on the starter can lead to severe issues. Regular engine inspections can assist you in identifying any leaks and addressing them accordingly.

Read More: Oil Leak Symptoms and Causes

6) Fuse Problems

Vehicles typically have two fuse boxes, and a blown fuse can impact the starter, rendering it non-functional. Replacing the fuse will resolve the problem.

Starter Motor Location

The location of the starter varies according to the vehicle model. The starter motor is usually installed at the rear of the engine block, close to the flywheel, and positioned between the transmission and the engine.

Accessing it can be challenging due to its placement at the back of the engine. Typically, it is bolted to the engine block; however, in some instances, it may be mounted on the gearbox facing the engine.

How to Troubleshoot a Bad Starter

• Park your vehicle on a leveled surface
• Open the hood and locate the battery
• Inspect the vehicle’s battery and battery cables, as defective cables or a depleted battery could be the cause of the issue.
• Gently tap the starter with a solid object—this can occasionally help activate it.
• Attempt to move the car from “park” to “neutral.” If the car starts in neutral, it might indicate a technical malfunction.
• It’s time to check the fuel. Check the fuel level by checking the fuel gauge.

Read More: Symptoms and Causes of Bad Shift Solenoid

Starter Motor Replacement Cost

The replacement cost of the starter motor varies according to vehicle model, labor cost, and type of part’s brand. The average replacement cost of the starter is from $240 to $920. In this cost, the labor cost is from $80 to $510 while the starter itself cost is from $160 to $410.

How To Test a Starter

FAQ Section

What is a Starter?

A starter is an electrical device that cranks an IC engine to start its operation. As you turn the car’s ignition switch, the starter motor gets power from the battery. When it gets power, the electromagnet within the starter motor prompts the pinion gear of the starter drive to engage with the transmission’s ring gear, which in turn powers up the engine.

How to bypass a bad starter?

To “bypass” a starter, the simplest method is to connect a wire between the starter motor’s positive cable and the starter solenoid. This will help to start your engine if fitted on the car, so ensure the vehicle is in neutral and that no fingers are near any rotating parts.

Can I jump-start a car with a bad starter?

When the starter becomes faulty, jump-starting the car will not be helpful, as the starter already has power supplied to it, and that isn’t the issue. But when the starter becomes faulty due to a dead car battery, jump-starting can be beneficial.

How can I tell if it’s the battery or the starter?

The most straightforward method to find if the issue lies with the starter or the car battery is to check the voltage of your battery using a multimeter. Have a friend sit in the vehicle and crank the engine while you take the battery’s voltage reading. If the reading falls between 11 to 13 volts, the car battery is in good condition.

What are the causes of a bad starter?

• Loose wiring around the starter
• Corroded connections
• Corroded battery
• Worn-out starter parts
• Oil leaks
• Fuse problems

Read More

• Bad Fuel Injector Symptoms and Causes
• Bad Ignition Coil Symptoms and Causes
• Engine Oil Color Chart
• What Does Milky Oil On Dipstick Mean?