Won't Start?
Cars,  Auto Engines

Car Won’t Start? [15 Reason Why]

Starting your car and not having it turn on can be very frustrating. I have accidentally left my lights on, and come to find the next morning that the battery is drained and the car won’t start. Luckily many newer cars help you avoid this mistake, but they may be other reasons your car won’t start. 

Your car may not start because of human error, wear and tear, and common service needed for your car. Turning the key and listening may help you figure out the problem. If dashboard lights turn on you know there’s usually a problem. First, check the battery, gas levels, and human error. Then continue if needed.  

I know I can tell if my battery is going to die when things like starting the engine become difficult. Your attention to past days can give you a clue as to what might be the problem. Think of what happened and any sounds that are different. If needed you can tell a friend or mechanic that can help you find the problem.

Below we’ll discuss the many reasons that cause cars not to start. 

1. The Gas is Low

If you’ve ever tried to start your car and the engine turns over and over without starting, then it’s time to check the gas level on your dashboard. While this might not happen to you, chances are you have been low on gas a few times. If one of those times when you were low on gas, you parked on an incline, there’s a possibility that the gas might not make it to your engine.

If you suspect that you have a bit of gas left and the gas station is very close, you may be able to move your car to a level area and try starting the car again.

Make sure to consider all the safety precautions before any such move. Moving a car without the engine on can be difficult. Some situations will not be safe to move your car, especially since most cars need to be running in order for the brakes to work effectively on all four wheels.

When on level ground there’s no need to press the gas pedal, just turn the key and wait a bit for the gas to reach the engine. 

A safe way to get gas is to call a roadside assistance company. They can bring you enough gas to get to a gas station.

2. The Battery is Dead

The battery is one main reason cars don’t start. Most people will know right away if the battery is the culprit when the engine either doesn’t turn over or it turns over slowly and stops. 

You can turn on the light to check how they are operating and if your dashboard is dim. If you forgot to turn off the overhead cabin light, the alarm went off for a long period, or you left a radio on all night, then you know the battery is probably drained a bit. 

Even when the battery is drained you can sometimes start the car. If you left something on, turn it off and remove the key from the ignition switch. Wait about five minutes and then try starting the car. The battery can recover a bit of power to help turn over the engine after it has has a chance to sit for a while without any load on it.

If that doesn’t work you can try again in an hour, or get some help. Some people like to carry a portable jump starter in their car in case this problem occurs. Others will call a service like AAA to help them jumpstart their car or ask a friend for help. Just make sure to connect the batteries on both cars properly

Sometimes leaving a cabin light on for a couple of hours is perfectly fine, but if the battery has corrosion on the terminals and it needs to be cleaned off so proper contact with the cable is made. Check the battery terminals for any type of corrosion.

If you have corrosion, having a small tool kit in your car can be handy. You’ll usually need a wrench, socket, or pliers to loosen the bolt or nut and detach the cable.

For modern cars, you can use an OBD2 memory saver (amazon link) to prevent your car’s computer memory from resetting. (see video

To clean the terminals, first remove the negative or black wire from the battery first, for safety reasons. Then remove the red cable. Try to keep them from touching any metal.

Use a wire brush, or if you’re at your house use some diluted baking soda to help neutralize the corrosive acid that is on the battery cables and battery terminals. Scrub them until they’re clean and then make sure they are dry before replacing the battery cables and tightening them. 

Use a dielectric grease to coat the terminals or WD40 to help protect from corrosion occurring in the future. Be sure to replace the positive cable first, then connect the negative terminal. You can then remove the OBD2 memory saver if you used one. 

Check to see if your car starts. If it does then you’ll need to make sure you charge the battery and continue to monitor it over the next few days. You can either charge the battery by driving the car for 30 minutes or you can use a battery charger (amazon link). Some battery chargers can help repair some damage done to batteries. 

If the battery still seems low the next time you start it, the battery may need to be replaced or the alternator may not be working effectively. 

3. The Wiring is Loose

Loose wiring can occur on many cars. Older cars, cars with lots of mileage, and cars that operate in bumpy conditions tend to have items that become loose. Wiring can loosen from weathering, vibrations, work done by mechanics, heat, and natural aging.  

After you’ve turned off the engine, you can check under the hood for loose wiring. A flashlight can be helpful, as well as a pair of gloves. The wiring around the battery and alternator should be checked for a solid connection. If you see corrosion in the wires, check to see how bad it is and replace the wiring if needed.

Reconnect any loose wiring, ensuring that when you pull it, no slipping occurs. Any wires that are not in their correct place should be moved and secured (amazon link) to be free of any heat and moving parts. 

4. The Belts are Damaged

Every car needs a belt to operate the engine and the electrical systems of car. If a belt is damaged or loose, some systems of the car cannot operate effectively or at all. The alternator is one of these components the requires a belt.

When a belt is loose it will not grip the pulley and turn the parts of the engine that operate the car, like the alternator. Look and see if the belt has cracks, feels like you can move more than an inch when pulled on, or shows signs of rubbing against something.

You can also check the pulleys are secure and not wobbling. If something is wrong with the belt, check to see if it needs replacement or tightening. 

A loose belt or pulley could cause the alternator to charge the battery ineffectively. You may lose battery power over time. 

5. The Starter

Starter Removal and Installation

If the car does not start at all, the starter or battery could be non-functional. It’s always important to check the wiring before coming to any conclusions, and see if any electrical components are working. If you have an OBD2 scanner, this would be a good time to use it to check for problems,  especially when you see the check engine light is on. 

After your inspection, consider any other ideas of why the car might not start, taking into consideration the past performance of the car and any strange noises that you may have heard. If you are not sure what to do next get some help from a friend or mechanic. 

6. The Car hasn’t Been Serviced

Sometimes the problem with a car can be the engine. An old engine that is ready to retire or that hasn’t been maintained well may have difficulty turning over. There could be a number of reasons for this, so it’s best to go get all of your fluids changed if it’s been a while and has someone takes a closer look at your car.

All cars have problems with parts wearing out as they age. If there’s an internal problem with your engine that is causing the car not to start, then you may hear more noise than normal.

Getting an inspection of the car by a mechanic may reveal other issues with cars that haven’t been serviced for a while. Try to keep a regular schedule of maintenance and your car can last for a very long time.

7. Clogged Fuel Filter


If the fuel is not getting to your engine for some reason the car doesn’t have enough fuel to start. It will likely turn over just fine but you won’t hear it firing. This is an easy fix on most cars. You just need to replace the fuel filter which shouldn’t cost too much.

If you are wondering why the fuel filter got clogged in the first place, it may be that your car is old and the filter hasn’t been changed in a long time. Particles start to accumulate over time and clog the filter. Another common reason the fuel filter gets clogged is low-quality gas.

If you need to change your filter anyways, then you can get them for cheap and see if the problem gets betters.

8. The Alternator


Your alternator controls how much power is being produced to charge your battery and provides electricity for your car to run properly. An alternator with faulty wiring or a belt that is loose can make it difficult for the car to start.

See if you can see if the belt is worn or broken. Check that the wires are connected and there aren’t any problems. Sometimes securing or replacing a wire can help. Likely it is a belt that will need to be replaced.

Sometimes an alternator starts to go bad but it’s not likely to completely stop working, but that might happen once in a while.

9. The Ignition Switch

Keys - car keys in ignition

Your ignition switch can have problems from lots of keys and accessories on your keychain, a recent accident, and if something on your steering column has been worked on recently.

The heavier your keys, the more pressure is exerted on the ignition switch. After a while, this can cause the mechanism to break. You will likely need a new ignition switch installed to help you turn the switch easily.

If your car has been in an accident recently and you haven’t checked out what repairs might be needed, your ignition switch could be damaged or need adjusting.

Sometimes the wires leading to the ignition switch can get disconnected from an accident or recent work around the steering column. Getting the wires checked out can help.

10. The Spark Plugs

car spark plugs

Your sparkplugs are essential to helping ignite the gas in your engine. If the wiring to the sparkplugs is starting to fail or the sparkplugs are getting old, your car may not start as well.

Regularly replace sparkplugs and sparkplug wires according to your car’s maintenance schedule to ensure you have a clean spark in the combustion chamber to ignite the gasoline. Then your car will start much easier.

11. Forgot A Step Before Starting Your Car?

brakes without engine on

Sometimes we are in a rush and forget to go through the normal procedures of starting the car for some reason.

Ensure you’re placing the correct key in the ignition switch.

Ensure the gear is in the park.

Ensure you step on the break.

Ensure the steering wheel is turned a bit before turning the key in the ignition. When the steering wheel is locked you may need to turn it just a little, then you will be able to turn the key.

These rules apply to most cars and forgetting one of these steps may cause the car to prevent you from starting it.

12. The Air Filter

Check your Air Filter

Similar to the gas filter, the air filter can get clogged from time to time. Of all the fixes for your car not being able to start, this one is probably the easiest. The reason for this is because most air filters are easy to remove and replace.

Open the air filter under the hood and check to see how dirty it is and if there is lots of debris or dirt in the filters. If the engine doesn’t have enough air flow the engine won’t be able to start.

13. The Temperature

Cars covered in snow during snowstorm in Montreal
Cars covered in snow during snowstorm in Montreal, December 2016.

Ensure that the car isn’t too cold. Sometimes a battery or fuel line can freeze. When this happens the battery can’t produce enough electricity for the starter to crank. If the fuel line is frozen gas can’t get into the engine for combustion to start the car.

Keep the car warm in a garage or other shelter to help prevent freezing. Sometimes you’ll need to wait til the temperature rises to try to start your car again.

14. Bad Keys

keys worn down_

Sometimes keys can get worn down. Sometimes keyless car transmitters lose battery power. When these things occur you might not be able to start your car.

If you have been using the same key for a while and it’s worn down, try to find that spare key you have for your car and see if it works. If it works well, make a copy and retire your old key.

For your electronic key, you may need to replace the battery. Your owner’s manual should let you know.

15. Fuel Pump

check fuel pump pressure
Photo Credit: http://www.aa1car.com/library/fuel_pump.htm

A fuel pump helps pump gas to your engine. Then your cylinders can fire to help start your car. If the fuel pump is failing or not working, your car may not start.

In some cars, you may even hear the fuel pump make noise when you turn your key to the accessory position, but it’s likely you won’t. Get someone to help you find and test your fuel pump and decide if you need to replace it.


When making a guess at what is causing your car not to start, doing some basic investigation or diagnosis can be very effective. Look for: gas levels, battery condition, wire connections, belt damage, starter issues, and consider when your car was last serviced.

Start inside the cars by checking the dashboard, lights, and starting the car to find problems. Then move to look under the hood, and visually checking different parts that may be causing the car to not start. You may need to use gloves to inspect other areas under the hood. 

Finally, get some help if needed to resolve the issue. I hope you can get your car to start and have a safe drive. Try this article to learn more about do it yourself tune-up –DYI Tune-Up Guide.