A car that won’t start can be a major headache. But knowing some basic car troubleshooting tips can help you save money on roadside assistance and potentially avoid unnecessary repairs.
The first thing to check is the battery. Look for corroded terminals that restrict the flow of electricity or a weak click when turning the key.
1. Dead Battery
Whenever your engine fails to crank over, the first place you should look is the battery. If it’s old, has a parasitic draw from unneeded electrical devices (like a radio or aftermarket alarm), or has suffered from heat damage, it may have reached the end of its lifespan.
A dead battery will either produce a clicking sound or be completely silent when you turn the key. You may also notice a rotten egg smell. If you do, call roadside assistance to prevent the battery from leaking, as it has lost its reserve charge and will fail soon.
Then, you’ll need to replace it. A failing alternator, starter, or ignition switch could also cause your car to not start. Each has its own unique problems.
2. Failing Starter
If you turn the key and nothing happens, or the engine cranks very slowly, your starter may be having problems. It is important to understand how the starter works and when it needs to be serviced. Jump-starting can be a temporary fix, but if your starter fails, you’ll need a professional to inspect it and replace or repair it.
The starter is an electrical motor that connects to the battery and spins the flywheel to start the engine. It takes a lot of power to do this and can wear down over time, especially in extreme temperatures.
A clicking noise or a burning smell are common signs that the starter is starting to fail. This can be an expensive problem to solve and should be addressed as soon as possible.
3. Failing Ignition Switch
When you turn the key and hear nothing but a weak click, it’s an infuriating moment. Whether you’re in the parking lot after dinner or at a stop on the motorway before work, the last thing you want is for your car to refuse to start.
A faulty ignition switch can disrupt power to the vehicle’s fuel system and starter, which prevents your engine from starting. Another sign of a failing ignition switch is trouble powering on the vehicle’s accessories, like the radio and dashboard lights.
To check your ignition switch, try jiggling the steering wheel while turning the key. If this doesn’t help, you should enlist the services of a professional. Faulty main fuses and fusible links can also cut power to the starter and engine control unit, so these should be checked too.
4. Failing Spark Plugs or Ignition Coils
The starter motor and ignition coils require electrical power to function, and if they fail or don’t get the proper voltage they won’t start. A failing alternator, bad battery or loose spark plugs can all drain the system’s energy. A hot engine can also cause spark plugs to heat up faster, degrading them sooner than their lifespan.
Failing ignition coils create a weak spark that can’t keep the air-fuel mixture combusting, leading to engine misfires, rough idling and poor fuel economy. Replacing them on schedule reduces their risk of failure and helps you avoid a roadside breakdown. If you notice a flashing check engine light, have it inspected promptly to confirm a bad ignition coil or spark plugs are the problem.
5. Failing Fuel Pump
If your car starts to jerk or stall while driving, it could be due to a failing fuel pump. This is especially true if the lurching and hesitation occurs at highway speeds, which is a sign that the fuel pump is not delivering enough fuel to your engine.
A healthy fuel pump maintains steady pressure at the fuel rail so that the engine gets the right mix of air and fuel. Weak fuel pumps don’t always create a problem when starting the car, but they do tend to show up when the engine needs more power like climbing hills or when towing. That pattern indicates that the pump is not keeping up with demand and will eventually fail completely. You may also notice a stale fuel smell when attempting to start the car.
6. Failing Alternator
Cars need a lot of electricity to start. That’s why the starter motor draws up to 350 amps to turn over the engine. The rest of the car draws far less, with electrical accessories like the radio or headlights drawing about 30 amps at most.
A failing alternator can drain a battery, leaving the starter with no power to engage. That’s why many newer cars have a warning light to indicate a battery or alternator problem.
Other signs of an alternator problem include a swollen battery (which can release dangerous sulfuric acid), whining or silence when turning the key. If you suspect a problem, make sure to call your trusted mechanic right away. They can help you diagnose the problem and fix it before it gets worse.
7. Failing Wiring
Failing wiring can cause problems in a variety of ways. A faulty wire can cut off power to a component and prevent it from functioning. A wire problem can also cause a short that could burn out your battery or other electrical components.
If you notice that your car’s fuses are blowing frequently, this is another sign of a wiring issue. Fuses are designed to protect electrical circuits from overdrawing, and when they begin to fail, it can prevent vital components like the ignition system from working.
Look for a burning smell or discoloration near a fuse to determine if it’s time to replace it. Failing fuses can also cause the lights in your dashboard to flicker or stop working. Detecting and addressing wiring issues early can save you time, money and stress.
