There are a thousand and one things that could potentially go wrong with your car on any given day. You could have a problem with the windows not rolling down, your heater blowing cold air, a weird smell in the cabin or a strange rattling noise coming from under the hood. But of all the issues that you have to potentially deal with when it comes to your vehicle, nothing is more frustrating than realizing your car is simply not going to start today. You put the key in the ignition, you give it a turn and maybe you hear a click, maybe it struggles a bit, maybe you get absolutely no response whatsoever. It's the worst.
If you need to drive to work, go pick up groceries, or head out on a road trip it can be infuriating if your car isn't going to respond to you. But it's hard to diagnose a problem when nothing's happening whatsoever. With that in mind, we can fill you in on the most common causes for a car simply not starting. If you are stuck in the driveway with nothing happening check out these potential issues and you may be able to narrow down what's going wrong so you can get it fixed a little bit sooner
One of the most common reasons for a car to not start is that the battery has died. When your battery isn't working then your spark plug will be unable to create the spark that ignites the air and fuel mixture in your combustion chamber allowing your engine to turn over. No spark means no power. And the battery is directly responsible for that.
The battery in your car could have died for any number of reasons. To start with, your average battery only lasts three to five years to begin with. If you've been running your car with a battery for that long, then there's a good chance it's coming to the end of its life. Additionally, in extremely cold weather a battery is going to perform much less efficiently than in the warm weather. That's because the chemicals that create the energy in the battery are sluggish in cold weather and can't work as well.
If you've left any of your electronic components on by accident overnight, especially the headlights, then your battery will likely have been drained to the point of being dead as a result. It's also possible you have something like a loose wire or severe corrosion around the contact points preventing the battery from working properly as well.
If you're hearing a click when you turn the key in your ignition and nothing else is happening, this is very likely an electrical issue. You could attempt to jumpstart your car either with a portable jumper or by finding a good Samaritan who is willing to give you a jump start from their car to see if that fixes the problem. If a jump start is able to get your car working again then you know for sure the battery was the issue you were dealing with. Although there is a chance that the alternator was the source of the problem as well because they work together to power all the electronic parts in your vehicle.
If the jump start doesn't work to restart your vehicle then the battery still could be the problem, but it could be so dead that even a jump won't get it started. Replacing the battery will obviously solve this problem for good but you should test it with a multimeter first to see if it still has a charge. The multimeter should read 12.5 volts to 12.6 volts on a good battery. If you're reading 12.3 or below then your battery is definitely running low on a charge and will not be working very well.
2. Bad Starter
If the starter in your car is broken then obviously your car won't start, that sounds like it makes sense, right? The starter is the electrical motor that connects to your battery. When you turn the key in the ignition power goes from the battery to the starter. That sets the engine in motion by turning the crankshaft and getting the pistons moving after you turn your ignition switch. The engine starts moving, the fuel and air mixture gets injected into the chamber, the spark ignites it and your engine is now powering your vehicle. But, if the starter motor can't perform its job, then your engine will be unable to perform its job as well.
A bad starter motor means that your engine simply can't crank. You'll hear that clicking sound or another loud sound but nothing else will happen.
3. Clogged Fuel Filter
This is one of the potential causes for your car not starting that a lot of drivers don't immediately think of. If your fuel filter is so badly clogged with debris that gasoline is unable to travel from the tank to the engine then your car is going to have a hard time starting. This will cause a lot of strain on your fuel pump, but there simply won't be enough fuel to reach the combustion chamber where it can actually ignite and start your vehicle.
Changing a fuel filter is one of those routine maintenance jobs that you should conduct as a driver every now and then. The recommended period of time for changing your fuel filter can change from vehicle to vehicle so the best bet is to check your owner's manual to find out exactly how long yours can last. In general, a fuel filter will last for around two years or 30,000 miles. That's a basic rule of thumb and will give you a tentative guide on what to do with it. If you haven't changed your fuel filter in longer than that and your car isn't starting, then this may definitely be a place you want to check
4. Bad Ignition Switch
A bad ignition switch is another potential cause for a car not starting. If you're sure the battery isn't the source of the problem, but your car is still refusing to turn over, the ignition switch may be the source of this issue. You can attempt to diagnose this one by simply using the headlights on your vehicle. If the headlights work fine when you turn the switch, but your car won't turn over when you turn the key, then you likely have a perfectly fine battery but a bad ignition switch.
5. Bad Timing Belt
The timing belt in your car connects the camshaft to the crankshaft. As the crankshaft rotates and the pistons rise and fall in the cylinders, the timing belt ensures that the camshaft is synchronized with it so that the valves open at the exact right time. If your timing belt breaks as you are driving, the valves would remain closed as the cylinders rise causing them to crash into each other. This is essentially a catastrophic engine failure that would shut your car down right away and bring with it an extremely expensive repair bill.
If your timing belt happens to break after you've safely stopped your vehicle, perhaps the stress of just trying to start your engine caused it to snap, then you can count yourself lucky. You probably just avoided an extremely dangerous situation out on the road, and you may have saved yourself a much more expensive repair bill. Timing belts should be changed every 60,000 miles or so, or about every five years. Many vehicles these days use a timing chain rather than a timing belt which is made of metal and is much more durable. You can check your owner's manual to find out for sure what your vehicle has. If it has a timing belt, then it's very possible that it broke, and you need to get a replacement. This is not the cheapest repair job in the world by any means and replacing your timing belt can cost you upwards of $500 to as much as $2,000 depending on the make, model, and year of your vehicle.
6. Broken Distributor Cap
This is another cause of your car not starting that the average driver won't think of right off the bat but it's one that's worth checking out if none of these other causes are the reason why your car is giving you trouble. The distributor cap is what sends the voltage from the engine's ignition coil to the spark plugs. If it happens to get contaminated with moisture it can end up causing problems transmitting that current. You can try to fix this by wiping it with a clean dry cloth and then reinstalling it. If the cap is actually broken or damaged, then you're going to need to replace it entirely. You can get a distributor cap replaced for generally between $100 and $150.
7. Bad Ignition Coil
Your ignition coil is what transforms the voltage from your battery into an electric spark. When you don't have a functioning ignition coil then you're not going to be able to convert the voltage into the spark necessary to ignite your fuel and air mixture. The same multimeter you used to test if your battery is working can be used to test the ignition coil as well. When you test your ignition coil with a multimeter you should get a primary system current that falls somewhere between 0.4 and 2 ohms. If you're getting a zero, then you have a short. You could also test the secondary circuit of your Ignition coil which should have a resistance that is somewhere between 6,000 ohms and 10,000 ohms. The best thing to do is check with the manufacturer to get the exact range, however. Again, if you're getting the zero, then your ignition coil has shorted out and you'll need a new one.
8. Out of Gas
Yes, this is a silly explanation for why your car won't start but you'd be surprised how often this ends up being the case. We all like to think we know that there's gas in the tank but sometimes it can slip your mind, sometimes there could be a leak, or sometimes if other people in the house drive your car they may bring it back on empty leaving you in a lurch.
Being out of gas is probably the most obvious reason why a car isn't going to work, but it's definitely one you should at least take a look at. If you've ever called tech support for a problem with your computer, you know that the first question the tech person asks you is whether or not your computer is plugged in and turned on. And ninety-nine times out of a hundred that question makes you roll your eyes because of course your computer is turned on and plugged in. But there is that one in a hundred times when you realize the power cord got pulled out by accident and that's the reason it's not working. It makes you feel foolish for not thinking of it sooner, but sometimes that's all it is. Check your gas tank and see if you need a fill up before you get started.
The Bottom Line
As you can see there are a number of reasons why your car is going to shut down on you and refuse to start sometimes. As frustrating as it is, at least you can have a good idea of where you can start looking and eliminate each potential cause in turn to try to get to the bottom of what's causing your car to not start in the first place. Once you know exactly what you're dealing with and what you're not dealing with it's going to be a lot easier to get the problem fixed and then save you some time and money so you don't have to worry about diagnosing 100 different things.
Just remember, as frustrating as it is, there are only a handful of problems that are going to cause this to happen to you. Check each potential issue one at a time until you figure out what's going on and then you can act accordingly.