Nothing is more frustrating as a driver than getting into your car, turning the key in the ignition, and realizing your car simply won't start. Maybe you'll get some clicking sounds, or even the sound of the engine struggling to get going, but it simply refuses to engage. For a lot of us, cars are a vitally important part of everyday life. You need them to get to work, to buy groceries, to get to friends and loved ones. If your car isn't working, it can really upend your entire day. Unfortunately, there are a whole host of reasons that your car could stop working on you. Knowing what causes your car to fail on you can be a tricky thing to figure out. With that in mind, let's take a look at some of the most common reasons that your car won't start and what you can do about it.
13. Dead Battery
One of the first things that you should check out when you're having problems getting your car started is your battery. If it's not the most common reason for your car to not start, it's certainly one of the top reasons. When you put your key in the ignition if you're not getting any lights or other electrical components to turn on at all, you can almost guarantee that your battery has died on you. This could be the result of your lights having been left on by accident overnight, or just because your battery is too old at this point. You only get three to five years worth of life out of a battery and after that it will not hold enough of a charge to allow your vehicle to function any longer.
If you're pretty sure the battery is the culprit for your car not working you can get a jump start from a portable jumper or from another car. If everything works fine after the jump start that confirms the battery was the problem. If it just drained by accident you may be fine if you let your car run for a while so the alternator can recharge it. However, if the battery is old you may still want to look into getting a replacement as it is likely to keep dying on you.
12. Bad Spark Plugs
Although there are a number of parts of your vehicle that require routine maintenance one of the ones many people forget are the spark plugs. Your plugs are only going to last you from around 20,000 miles to 100,000 miles depending on the kind of plugs you are using. Cheaper plugs will only last a short while, well more expensive platinum and iridium plugs will go the distance up to a hundred thousand miles or so. That said, if your spark plugs have been worn out, then they can't create the spark necessary to ignite the fuel and air mixture in your engine and that means you're not going to get your car to start. It's unlikely that all of your plugs would fail at once, but if you're having issues with engine misfires and rough idling and other spark plug related problems that have led up to your car not starting, then you could definitely do with taking a look at your spark plugs. Also, it's just good to know when you actually change them last to see if it falls in the window where they might have failed on you.
11. Bad Alternator
If you're having issues with the electrical system in your car and the battery isn't the cause then you'll definitely want to take a look at your alternator. When your alternator fails it's unable to keep your battery charged and that means your electrical systems are all going to suffer as a result. The two work together to keep everything running and if one fails, the other is likely to follow. Your alternator can fail if the drive belt wears down or slips off. Dimming headlights and a slow cranking starter are usually good signs that you're having an issue with your alternator.
10. Bad Starter Motor
If all you're getting is a clicking sound when you try to start your car, there's a good chance your starter motor is to blame. Since the starter is responsible for the engine turning over, if it's not able to function that obviously you're not going to be going anywhere when you try to get your car started.
9. Bad Air Filter
If the air filter in your car has become so clogged with dust, grease and debris that air simply can't travel through it anymore then your car's intake will be unable to draw air in. Air is one half of the mixture required for combustion to work in your engine, along with fuel, so if there's no air there can be no combustion. Your air filter needs to be really clogged for this to happen, you likely would have experienced problems starting your vehicle before this happened, but if you swap out your air filter with a new one which will only cost you about $10 to $20 on a site like AutoZone, it should clear up the problem if this is the source.
8. Bad Fuel Pump
When your fuel pump fails it will remarkably diminish your car's ability to get gasoline from the tank to the fuel injectors and into the engine. If your fuel pump can't get the gasoline from the tank to the engine, then there's nothing to burn to start the combustion reaction when you turn your key in the ignition. A fuel pump replacement can be quite a pricey repair job if you need to have yours swapped out, costing anywhere from $700 to as much as $2,000 depending on the make and model of your vehicle, and the mechanic you take it to, to get it fixed.
7. Bad Timing Belt
A timing belt is essential for the proper functioning of your motor. It connects the crankshaft and your camshaft so that they rotate together which allows the pistons to rise and fall in synchronous motion with the valves opening and closing. If your timing belt doesn't work, then the valves in your engine will not be able to open and your engine will fail completely. If your timing belt failed while you were in the middle of driving, it would actually cause some catastrophic engine failure and likely lead to thousands of dollars worth of repair bills. However, if it breaks just as you're trying to get your car started you may be able to avoid that extensive damage, but you'll still be unable to start your vehicle.
Many vehicles these days have switched to timing chains, which are made of metal, instead of the more fragile timing belts. However, if you do have a timing belt you definitely need to keep it maintained and you'll probably need to have it replaced every 30,000 miles to 60,000 miles. Your owner's manual will be able to tell you for sure.
6. Busted Distributor Cap
In your engine the distributor cap is what sends the voltage from your ignition coil to the spark plug to get your car started when you turn the key in the ignition. Distributor caps are sometimes subject to failure caused by moisture getting under the cap or the cap itself can break and no longer function properly. If you can take a look at the cap and see that it seems to be in one piece still you can try using a clean towel to wipe it dry. However, if that doesn't work or the cap is clearly broken it's going to need to be replaced. On average a distributor cap costs between $20 in $40 on a site like autozone.com.
5. Security System Problems
If your car has a security system it's possible that it may have glitched on you in some way. Modern vehicles, especially those that use keyless entry and remote starting devices, can occasionally fail in a way that makes the security system think that you are a thief trying to access the car. This could be the result of a problem with fuses or other electronics, and faulty sensors. If your car's computer is registering that you're using the wrong key to try to access it, it can lock up and prevent you from starting because it thinks you're a thief.
4. Bad Ignition Coil
The ignition coil in your car is an induction coil which means that it takes the voltage from the battery and is able to convert it into the thousands of volts needed to actually get your car started. It does this by sending that voltage to the spark plugs so that they can spark and ignite the fuel and air mixture. If the ignition coil doesn't work, then the power from your battery can't be used to star your vehicle.
3. Corroded Battery
It's possible your battery is the reason your car is not starting even though it still potentially has a viable charge in it. If your battery is suffering from severe corrosion, then the contacts are not going to be able to transmit the proper voltage for the battery to the rest of your vehicle. This happens sometimes in the case of leaks from the battery, or from moisture getting into the engine and on the battery as well. If you take a look at it and notice that there is a crusty white substance around the posts then you may be able to get your car working again by getting them cleaned up. A battery cleaning solution and a wire brush should be able to polish them up and get them working again. Just make sure you disconnect the battery carefully. When your car is off, disconnect the negative or black terminal first and then disconnect the red or positive terminal afterwards.
2.Bad Fuel Filter
Just like your air filter, if your fuel filter is too clogged to allow fuel to flow through it properly then your engine is not going to be getting the fuel necessary for a combustion reaction to occur. Your fuel filter's job is to prevent impurities from passing through the fuel lines, but eventually it's going to become so clogged it's no longer able to allow gasoline to pass through. Ideally you should be changing your fuel filter every 20,000 miles to 40,000 miles, although your owner's manual will be able to give you the precise timing for your specific model.
1. Out of Gas
Along with a dead battery, one of the most common and embarrassing causes for a car to not start is a simple matter of not having gas in the tank. Obviously, your car isn't going to work without fuel in it, but it does happen from time to time that the tank is run dry without us realizing it. This could happen if you simply forgot to gas up because you've been busy, or if a friend or family member borrowed your car and ended up wasting all your gas without telling you about it. It's also possible that a leak somewhere in your fuel line could cause this outcome. Whatever the reason, it's always good to check the tank and if necessary, add a bit of gas to the tank to see if that will fix your problem or not.
Even though this seems like the most obvious solution to the problem and one that you would never overlook, sometimes it really is this simple. Remember, sometimes the easiest way to figure out why something isn't working it's just to make sure you've got it plugged in and turned on. The same goes for your car, you need to make sure as a working battery and gas in the tank. Once that's taken care of, you can go back over some of these more complicated reasons for your car to not be starting.
The Bottom Line
Your car contains literally thousands of different parts that have to work together to make it function. If one system fails, you can have a cascade effect that causes many other parts of your car to fail as well until you have absolutely nothing working. Unfortunately, sometimes the only way you can figure out what's going on is by the process of elimination. Once you're confident you have gas in the car, once you know that your battery is still viable, you can go piece by piece until you figure out what's caused the problem and why your car won't start. If you can't figure it out yourself, you can always get your car towed to a mechanic to figure out what's going on.