There's almost nothing more annoying, your car won't start and you were already late! It can be frustrating and disappointing, but in this article we cover the most common problems. So in the best case you can solve it yourself or at least know why your car won't start.
Car will not start due to a flat battery
If a car won't start, a flat battery is the most likely problem. A flat battery can be recognised by:
- You can hear the starter motor spinning with difficulty
- You hear a clicking sound
- Light flashes when starting
- The central locking system does not work any more
- The dashboard no longer lights up.
A flat battery can be caused by burning interior lights. It often happens that someone leaves a light on by accident. Another cause can be an old battery that no longer charges sufficiently and cannot turn the starter motor. Another problem can also be a worn out alternator. This does not have to do with the battery itself but with the charger, the dynamo.
How do I start a car with a flat battery?
Fortunately, you can often start a car if you are dealing with a flat battery. To do this, you have several options:
- Is there anyone around with a car and jumper cables? Then put the jumper cables on the right poles, black on minus and red on plus. Then start the car and try to start your own car. If your car starts; leave the jumper cables in place for another 2 minutes. It is possible that the battery and therefore the car do not have enough power yet. One consequence may be that the car will stall again.
- Another possibility is to put the car (if manual) in 2nd gear. Then you need a couple of strong people to push you. At the right moment, with sufficient speed, try to let out the clutch. This can start the car, but it usually takes a few pushes.
- If you have a spare battery or another car, you can choose to install it. A battery replacement is not very complicated and should be possible in 10-15 minutes.
If you are pushed or you have used jumper cables, it is important that you drive for at least 20 minutes. Otherwise, there is a chance that the car will not start because the battery has not yet been charged.
TIP: If you are a multimeter If you have a battery, check the battery voltage and it should be more than 12 volts.
Problems with the engine itself
To understand what can go wrong with an engine, let's look at what happens when you want to start it. The first thing any driver does after getting into a car is to put his key in and turn the ignition switch. Then the charge from the battery goes to the starter motor that turns the crankshaft. Meanwhile, fuel from the fuel tank is pumped into the engine through the fuel pump, then through the fuel lines, the fuel rail, and finally the injectors.
At the same time, air is drawn in through the air filter and enters the engine through the intake manifold. In the case of a petrol engine, a distributor sends sparks into the engine through the spark plugs. This ignites the air-fuel mixture and voila, there's your horsepower.
Ignition system
Alternator not working properly
The alternator is the device that draws power from the engine and charges the battery when the vehicle is running. It is essential for the electrical cycle of a car, as its failure can prevent the car from starting.
If charging does not take place, the electrical systems in the car will draw power from the battery. This can eventually drain all the juice from the battery, killing it. In order to start an engine, the starter motor needs a good surge of electricity from the battery. In this case, the battery does not have this electricity.
Check the alternator
Checking the alternator is an easy job. Start the car with a starter cable and measure the voltage at the battery terminals with a multimeter. If it is less than 12 volts, the battery may be dead. But the main event we expect is an increase in voltage when you rev the engine. The alternator, if it's good, should be flowing a lot of electrons to the battery when the engine is running. If no change or a meagre increase in voltage is observed, it indicates that the alternator is not doing its job.
Problems with the starter motor
This is the third and last element in the ignition circuit. The starter motor is directly connected to the engine crankshaft. It turns the crankshaft to start the engine when we turn the key. A defective starter motor can be a reason why your car will not start but has power.
The diagnosis of this problem is quite simple. When you turn the key, it should start. The cranking of the engine is initiated by the starter motor. So, if the starter motor has died, turning the key will make no difference. No rotation, no desperate attempts to get the cylinders to fire. Just silence.
Problems with fuse and wiring
Before replacing the alternator, starter motor and battery all at once, check the fuse box first. If the ignition fuses are blown, a simple fuse replacement can get your car running. Do check what caused the blown fuse.
Fuel system
The fuel system is what supplies the engine with fuel. Petrol and diesel engines have different fuel system designs, but the general working principle is almost the same. So, if your car won't start, the fuel system could be a source of the problem. But the fuel system should be checked after the whole battery & ignition system is found to be faultless.
Faulty fuel pump
This is not a problem with most new cars. If your car is driven regularly and filled with proper gas/diesel fuel, it should not be a problem. Unless your car was fitted with a faulty fuel pump right from the factory. But, if your car is quite old or the fuel quality in your area is questionable, a faulty pump may occur.
The diagnosis of this problem is quite simple. If you turn your key to the ignition before cranking the engine, you can hear a hum coming from behind. This is the operation of the fuel pump. Before the car is started, the fuel pump supplies fuel and prepares it for injection.
But if you have a defective fuel pump, this cannot happen. The engine will not get its fuel and will refuse to start. So, if you turn the key and don't hear a hum coming out of the back, it may be a problem with the fuel pump.
But if you suspect a fuel pump failure, it should be checked. Maybe
it is simply blocked and unable to function. But that is for a trained eye to decide. A skilled technician is therefore needed for this work.
Low fuel pressure/blocked fuel lines or fuel rail
Your fuel pump may be working, but what if the fuel pressure is not reaching the injectors? A clogged fuel rail or fuel line could be a problem. Or it could be a problem with the fuel pump causing the fuel pressure to drop. Some fuel rails may have a Schrader valve on the fuel rail that allows you to test the fuel pressure.
If the fuel pressure is found to be low, you should give it to a mechanic for further diagnosis. But be aware, these problems usually only appear at high mileage.
Defective fuel injector
This is a rare possibility if your car will not start. If you have a four-cylinder engine, all four fuel injectors must stop working for the engine not to start. So this is a rare scenario, but still possible.
Air intake system problems
This is another rare problem that prevents a car from starting. If your car won't start, it could mean that the engine isn't getting everything it needs. We dealt with the starting movement and the fuel supply. Now let's focus on the air supply. The engine needs air to burn the fuel. If less air is pumped in, your car won't start.
Clogged air filter
In rare cases, a clogged air filter or air pipe can cause the engine not to start. Check for a blocked filter. Change the filter if necessary. Look as far as possible into the air duct leading to the engine to find dirt, animal nests, etc.
Defective air mass meter
The air mass meter ( MAP / MAF) measures the volume and pressure of the air pumped into the engine. If these sensors are defective, the engine may get a wrong measurement and not start. Disconnect these sensors and start the engine. If it starts, replace the defective sensors.
Spark ignition system (For petrol engines)
Diesel engine owners, you can skip this section. Petrol engine owners, read on. If your car won't start and has a petrol engine, it could be a spark problem. The system is important for spark igniters such as petrol or natural gas engines. So, what can go wrong in this area?
Problems with the ignition coil or distributor
The ignition coil and distributor are two important components of the ignition system. If they are defective, the engine does not get sparked in time and will not start. You can test them with a multimeter, but a mechanic is a better option.
Faulty spark plugs
Spark plugs ignite the fuel that is injected into each cylinder. They can wear out over time, leaving the engine with no spark to burn fuel, and your car will not start.
Removing the spark plugs is easy. Once removed, the spark plugs can be inspected for cracks or blockages. If the ceramic part of the spark plug is cracked, the insulation is affected, and it is a broken spark plug. If the tip of the spark plug is clogged with gunk or dirt, you need to replace it.
Spark plugs should be replaced as part of a service. By replacing them in time, you can avoid this problem.
Once you have the spark plugs out and they look OK, you can test them again with a multimeter. It measures the resistance across the ends of the spark plug. If it shows the wrong resistance across the ends, it's a faulty spark plug. If it shows resistance between any two points other than the ends, it is still a defective spark plug.
As you have read, there can be several causes for a car refusing to start. In most cases it has to do with the battery. And if you can't manage it, roadside assistance is often available within 45 minutes.
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