Everything You Need to Know About Car Starters

March 20, 2025

7 min read

March 20, 2025

7 min read

Starters are typically tough and long-lived. When they fail, they can leave you stranded until you find a replacement. Conveniently, replacing a starter is simple, provided you don’t cut any corners.

How a Starter Works

Two starters, sitting on a workbench. The starter in the foreground is new. It will replace the old starter in the background. — Replacing an old worn-out starter is a basic task.

A starter is an electric motor that spins the engine over to start combustion.

In the early days of the automobile, starting your car was a dangerous affair. You turned on the ignition and then turned the engine over by hand with a crank. It was bad news if your engine backfired. The kickback could break your wrist.

The electric starter changed all that. Using technology borrowed from cash registers, a small starter delivera a big burst of power for a short moment—just long enough to get an engine running.

A modern starter has two jobs: It pushes forward a little gear called a pinion gear so it meshes with the ring gear on your flywheel, which is what is connected to your engine. It must spin that pinion gear so that it turns the ring gear on the flywheel and starts over your engine. Here’s how a car starter works - opens in new window or tab. :

When you turn the ignition key, the battery sends power to the starter through a solenoid.
The starter pushes out its pinion gear and spins.
When the starter motor spins, it engages a toothed gear on the flywheel between the engine and transmission, which turns the engine over.
When the engine starts and you stop twisting the key (or stop pressing the starter button), the gear retracts and the starter stops spinning.

What Is a Solenoid?

A red standalone solenoid for vintage Jeeps and Ford trucks, displayed on a white background. — This old-school standalone solenoid fits an array of vintage Jeeps and Ford trucks.

The brilliance of the starter lies in the solenoid. The solenoid sits on top of the starter motor and converts the low-voltage electric current from the battery into a burst of high-voltage electricity strong enough to turn the starter motor. A starter solenoid is an electromagnetic switch that turns current from the battery into the mechanical movement of the starter motor.

When the key is off or in the run position, the solenoid is open, and thus the starter is not active. When the key is in the start position, energy from the battery causes the starter solenoid to close, which powers the starter.

How long does a starter last?

Starters should last a long time. It’s not unusual to see a starter last well past 150,000 miles, especially if the car is properly maintained and doesn’t lead a hard life. There are always exceptions to the rule, but generally, it takes a lot of age and mileage to kill a starter.

Cars that make a lot of short trips, get turned on and shut off and back on again many times a day, or are used in very cold or very hot environments might go through starters more quickly. That’s especially true if you combine hard use and extreme weather.

Starters hate being hot, so a car that makes a lot of short trips in warm weather without cooling down will use up a starter more quickly than a car that gets used, say, twice a day.

If your car has more than 100,000 miles and gets a lot of short-trip use, keep your eye out for the starter to fail.

What are signs of a bad starter?

The most obvious symptom of a bad starter is that your engine simply won’t turn over. If it does crank, a bad starter will often turn the engine over slowly, or sound labored.

For example, if your dash lights, stereo, and horn all work, but nothing happens when you turn the key, there’s likely a problem with the starter circuit. If you hear a click when you turn the key but the engine doesn’t turn over, the starter motor itself is probably bad. If there’s no click, check the starter relay first.

If you turn the key and nothing happens at all—no dash lights, nothing—you’re probably looking at a dead battery, not a bad starter.

Symptoms of a starter that is going bad but hasn’t fully failed aren’t as clear, but can still be reasonably easy to spot. If you hear unusual noises, such as grinding or clunking, when cranking the starter, chances are it is about to fail. In some cases, a failing starter will smoke, especially if it takes a lot of cranking to get your car started.

Replacing a Starter Is a Simple Job

A mechanic wearing a black nitrile glove reconnects the trigger wire after replacing a starter. — Reconnecting the starter trigger wire is the last step prior to reconnecting the battery wire.

Replacing a starter is a simple job that a novice mechanic can do in an afternoon. It requires basic tools, and it can be done in your driveway. Check out eBay’s detailed instructions and video - opens in new window or tab. .

You’ll need a jack, jack stands, pliers, screwdrivers, wrenches, and a socket set. With the car jacked up and supported, remove the negative battery terminal. Now the car is safe to work on.

The next step is to locate the starter. Remember, its job is to engage with the edge of the flywheel. It will be down at the base of the engine where it meets the transmission. Once you’ve found it, remove any wires or brackets blocking the starter. Then unplug or remove the starter trigger wire and ground.

From there, things are simple. Unbolt the old starter, slide the new one in, and bolt it back in place. After that, it’s a matter of plugging the wires back in, replacing anything you moved, and reattaching the battery cables.

Replacing a starter and solenoid together

On modern starters, the solenoid is part of the starter assembly itself, so you have no choice but to replace both the starter and solenoid at the same time. It’s also a good opportunity to replace the starter relay. The relay is often only a few bucks, and it’s worth doing for the peace of mind.

How Much to Spend on a New Starter

An old starter and a new starter sitting side-by-side in a green tray, with an array of hand tools. — When you replace a defective old starter, don’t throw it out. The core can often be returned for credit.

The cost of a new starter varies by vehicle, but good quality new parts usually start around $200. Use the eBay Parts Finder - opens in new window or tab. to narrow your search and grab the exact starter you need. Enter your year, make, model, engine, and trim to find a starter that fits your car. They are not necessarily interchangeable from one car to another. Even the same make, model, and year might come with a different engine and the starters may not match.

Starters are also expensive to make but simple to rebuild. What is sold as a “remanufactured” starter is an old starter with rebuilt insides. These are often perfectly fine substitutions for new parts, but sometimes they can be bad right out of the box. They’ll need replacing the moment they’re installed and tested.

You can find remanufactured, used, and no-name parts for less, but since the starter has such an important job, we recommend getting new, name-brand parts. The price might hurt initially, but paying upfront for good parts can save time in the long run. Remember, there are no shortcuts in car repair.

About the author

Aaron Richardson

Aaron learned early on that it's easier to be decent at a bunch of stuff than great at one thing, which led neatly to a career as a writer. He has been an automotive writer, a newspaper editor, and a business reporter, and has always worked on his own cars and bikes. When he isn't writing stories, he's wrenching on a '74 BMW 2002 or riding a motorcycle.

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This article is meant to provide general guidance only. Automotive maintenance, repair, upgrade, and installation may depend on vehicle-specifics such as make and model. Always consult your owner's manual, repair guide for specific information for your particular vehicle and consider a licensed auto-care professional's help as well, particularly for advance repairs.