5 Symptoms of a Bad Starter Motor (And Replacement Cost)

Every vehicle has a starter motor in it. The purpose of the starter motor is to spin the engine fast enough for the engine to run off of its own power. The starter is really just an electric motor that can be controlled by the ignition.

When you turn the key in the ignition, teeth on the starter motor engage with the flywheel or flex plate and spin the engine. The flywheel or flex plate is directly connected to the crankshaft, which pulls air and fuel into the combustion chamber as it rotates. Meanwhile, the spark plugs fire at a precisely calculated interval which allows the fuel inside the combustion chamber to be ignited.

This whole process is crucial for an engine to turn on and function properly. If your starter fails, there is a very good chance you are going to be stranded. 

Bad Starter Motor Symptoms

bad starter motor

When you have a starter motor that goes bad, the symptoms will be easy to recognize if you know what to look for. The best thing to do is to get your starter checked right away after you first notice these symptoms.

Below are five common symptoms you can watch out for which indicate that your starter is bad and possibly needs to be replaced.

Warning: when troubleshooting your starter, be careful not to touch the thick wire that connects the positive terminal of the battery to the starter. This is a hot wire that may shock you. It’s best to disconnect the battery when working on the starter if possible. 

1) Can’t Start Vehicle

trouble starting car

This will be the most obvious symptom that everyone should be able to notice. If you turn the key in your ignition and the engine won’t turn over, then the starter solenoid may be damaged or worn out Check the small electrical connector to the starter and make sure it hasn’t come unplugged over time.

If you drive an automatic, you might want to check your neutral safety switch as well. 

2) Smoke from Engine Bay

smoke from engine

If your vehicle is producing a lot of smoke and it continues to come out of it, then your starter might be shorted. The reason why smoke comes out is because electricity from the electrical supply is trying to pass through the shorted starter. This will result in a gray or black fog of smoke to appear from your vehicle.

3) Grinding Noise

A series of gears connects the flywheel and the starter together. Both components can cause grinding noises when they get too worn out. A bad starter motor will have grinding noises coming from inside of it and worn out gears will also cause these noises too.

Some failing starters may keep the starter gear engaged with the flywheel or flex plate even after the engine is running. This may cause a grinding noise or sound like the car is still trying to start, even when the car is already running. 

Either way, you should immediately take your vehicle to the mechanic so they can see which one is causing the grinding noise.

Related: What Does a Bad Starter Sound Like?

4) Freewheeling

If there is no cranking coming from the engine and you start to hear a whining noise coming from the starter, this is a symptom known as freewheeling. This indicates that your flywheel cannot make contact with the starter gear.

The starter solenoid is responsible for pushing the gear on the starter forward so it can engage with the flywheel or flex plate. Freewheeling may occur if the starter motor is able to spin, but the starter solenoid has failed.

5) Burning Smell

burning smell

Whether you see smoke coming out of your car or not, a burning smell inside and outside your car is an indication that your starter is bad. Most of the time, the smoke and the smell will occur at the same time.

Even if it doesn’t and you just have the smell, you should still get your starter checked out right away because the smoke may be coming next.

Starter Motor Replacement Cost

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starter motor replacement cost

Starters are positioned close to where the engine and transmission meet. The cost to replace a starter motor will depend on the repair shop or dealership that you bring your vehicle to as well as the make and model of your vehicle; some starters are much harder to access than others.

On average, you can expect to pay anywhere from $300 to $700 in total to replace your starter. The parts alone will cost you anywhere from $100 to $200 and the labor costs will cost anywhere from $150 to $500.

It is not the most expensive replacement job you will ever need but it is certainly one of the most important. After all, if you can’t start your engine, then you won’t be able to drive your car at all.

So, as soon as you recognize the symptoms of a faulty starter, get it replaced right away before you get stranded somewhere.

How to Extend the Life of Your Starter

1) Clean the Connectors

The battery and starter motor are connected through a series of special connector wires. If there is corrosion on the connectors or any other type of dirt or grime, it will limit the strength of the electric current that gets sent to the starter relay.

This will make it nearly impossible for the motor to generate enough power to fully crank the engine. Furthermore, it will ruin the integrity of the motor and cause it to become excessively worn out. So, you’ll always want to keep the connectors clean.

2) Tighten the Mounting Bolts

bad starter symptoms

The starter motor is held in place with mounting bolts. If these mounting bolts ever become too loose, then the drive of the starter and the flywheel won’t be able to engage each other. One symptom of this happening is a grinding sound whenever you try to start the engine.

To prevent this from happening, you should periodically check to make sure the mounting bolts on the starter motor are tightened.

3) Clean the Solenoid

The solenoid is the starter relay of the motor. On the top of the motor, it will appear as a small cylindrical object. The positive battery cable is what attaches to the solenoid from the battery.

It is the equivalent of the positive battery terminal. And like the terminal, the solenoid needs to be cleaned and maintained on a regular basis. All dirt, corrosion, and debris must be swept away if you see it there.

4) Clean the Terminals

The battery terminals are notorious for getting covered with corrosion. Battery acids produce hydrogen gas which will eventually find its way out of the battery once it has been used for too long.

These gases form the corrosive materials that you will typically see on a battery and its terminals after a couple of years. When the terminals are covered like this, the electric current which gets sent from the battery to the starter motor is weakened.

Cleaning the terminals will not only be good for the battery, it is even better for the motor as well.

Read also: 5 Symptoms of a Bad Car Battery and Replacement Cost

5) Inspect the Flywheel

overheated flywheel

The flywheel is a rotating device which assists the starter in cranking the engine. The front side of the starter has something called a pinion gear. This is the gear which engages with the flywheel so that the engine can be cranked.

Both the teeth of the flywheel and teeth of the gear need to be in good condition. If these teeth are cracked, worn, or missing altogether, then your starter motor will malfunction. You will need to replace the flywheel or pinion gear if their teeth are causing the problem.

If you continue to keep forcing the engagement between the two while they’re under these conditions, then it could wear out the starter motor more quickly.


4 thoughts on “5 Symptoms of a Bad Starter Motor (And Replacement Cost)”

  1. I owned a Nissan X Trail SLX AT M9R engine car. When I try to start ,there is a click sound from the engine compartment and does not start the engine. when I checked the battery, it was weak. I charged fully and tried. The car starts and I can drive three days. On 4th day car not started. As earlier a click sound from engine compartment can hear. I want to know what is the exact reason. Whether it’s the starter motor or battery. The electrician told me it’s the problem of bad starter. If I am fix a new battery and tried to start ; anything harm in it ? Can I solve the problem of not starting the car, after fixing the new battery? Or it’s better to replace the starter motor before renewing the battery ? Please help me.

    • Shouldn’t hurt anything to replace the battery, but before you do have it tested to see if your current battery is good.

      If you can knock on the starter to make the car start, it’s almost certainly a bad starter.

  2. I changed the starter in my 08 Dodge Avenger 2.4 and then try to start it and it cranks right up. But I came out the next morning and it wouldn’t start so I got to jump and it took a little bit but it started up then I get a burning smell so I turned it off. Could I have hooked up the wires wrong to the starter?


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