What causes a car to turn over but not start

Q: What is the first thing that one should check if an engine does not start crank?

You can typically hear it from the starters sound when turning the ignition. If the car is not cranking when you are turning the ignition switch to the start position, you may have a low voltage or a starter problem. If your engine is not cranking, ensure that the car battery is charged and in working order.

Table of Contents Show

1. Clogged fuel filter
2. Failed fuel pump
3. Bad timing belt.
What is the first thing that one should check if an engine does not start crank?
What sensors can cause a car not to start?

When it comes to automotive problems, few issues create as much stress for owners as a car that won't start. To make matters worse, this problem may stem from a variety of different underlying issues, which vary greatly in terms of severity and cost. Regardless, you will almost certainly need professional assistance to get your car running again.

Nonetheless, car owners can reduce their anxiety by better understanding the sorts of problems that may be at play.

The first step involves noticing whether your engine turns over or not. If your engine does turn over, but your car won't start, keep reading. This article outlines three possible causes of this relatively common problem.

Your car's engine generates power by combusting a mixture of air and gasoline. This process takes place inside the engine's cylinders. First, however, the piston must press the air-fuel mixture into as small a size as possible. This process goes by the name of compression.

Unless your engine achieves adequate compression, it won't start. A common reason for a lack of compression involves a flooded engine. A flooded engine simply has too much gasoline in it. This excess gasoline makes it impossible for the pistons to achieve an air-tight seal against the cylinder walls. As a result, when the piston presses down, the mixture of gas and air escapes around it.

In addition, excess gasoline coats the spark plugs and prevents them from generating the spark necessary for combustion.

Engine flooding often occurs if you pump your gas pedal too many times when trying to start your car. In some cases, you can resolve the issue simply by raising your hood and allowing excess gas fumes to evaporate from your engine for several minutes.

Chronic engine flooding can lead to the formation of deposits on your spark plugs. These deposits only make the problem more likely to recur. As part of a long-term solution, your mechanic may suggest installing all new spark plugs.

Engine flooding also happens when too much gasoline gets into your engine. Yet your car may also fail to start if it receives too little gasoline. This issue often occurs as the result of a faulty fuel pump. As you can probably guess, the fuel pump's job involves pushing gasoline from your gas tank to your engine.

To diagnose a faulty fuel pump, a mechanic begins by checking the appropriate fuse. A blown fuse can prevent a fuel pump from working, even if it remains in sound mechanical condition.

Next the repair technician will test your fuel pump relay. If the relay works properly, then the fault almost certainly lies with the pump itself. In most cases, you will need to install a new fuel pump.

Virtually all cars with electronic fuel injection systems contain a component known as the mass airflow sensor, or MAF. An MAF monitors the amount of air entering your engine. This information allows your system to regulate the amount of fuel it sends to your engine, thus maintaining an ideal air to fuel ratio.

Yet when a mass airflow sensor develops problems, it may no longer accurately measure the rate of airflow. As a result, your car won't have the appropriate data to regulate fuel usage. In some cases, a faulty mass airflow sensor won't detect airflow at all. In that case, the MAF instructs your fuel pump not to deliver any fuel to your engine.

This issue can prevent your car from starting up properly. For more information about diagnosing the source of your non-starting car, please contact the auto pros at Walnut Creek Import Service and Sales.

We have all been in that position where you have something important to rush to. But when you try to start your car, it does not start no matter how many times you try. Often this is a sign it needs maintenance. However, depending on how the car responds, there could be numerous reasons your car won’t start. It could either click but won’t start, crank but won’t start, or do absolutely nothing. This article will elaborate on the three possible reasons your car cranks but won’t start.

Start engine button | Getty Images

If you have ever been stranded on the side of the road with a car that won’t start, you know how frustrating it can be. Before you call a tow truck or a friend for help, it is helpful to rule out some potential causes yourself. Often, the problem is something small that you can fix on your own, saving you time and money.

When your car cranks but won’t start, it often means there is some engine turnover at the least. Cranking happens when you turn the key in the ignition, which sets off a chain of events that powers up the engine. If any issues prevent these steps from completing, the engine won’t start. According to Erie Insurance, here are the three main reasons your car cranks but won’t start.

1. Clogged fuel filter

A clogged filter is one of the most common reasons a car won’t start. The fuel filter, located between the fuel tank and the fuel pump, strains out any dirt or debris in the gas and keeps it from entering the fuel system. However, over time, the filter can get clogged with all that debris, resulting in less fuel reaching the engine.

With less fuel getting to the engine, there’s not enough to power it up and start the car. If this is the case, the best solution is to replace the fuel filter. Additionally, for future prevention of clogged filters, we recommend changing your car’s filter after 30,000 or every two years, whichever comes first. Axel addict also suggests checking the fuel injection.

2. Failed fuel pump

The fuel pump’s job is to move fuel from the tank to the engine. It uses an electric motor to create suction and pull the gas out of the tank. Once the gas is out of the tank, it goes through a filter and into the engine. If the fuel pump fails, fuel can’t get to the engine, making it impossible for your car to start.

The problem could be a simple relay issue that you should first check based on the owner’s manual or the result of a faulty or damaged pump. This issue is a relatively common problem, especially in older cars. If you think this is the problem, the ideal measure is to have a professional replace your fuel pump.

3. Bad timing belt.

The third possible reason your car cranks but won’t start is a result of a bad timing belt. The timing belt is a toothed belt that connects the camshaft, which controls the opening and closing of the intake and exhaust valves, to the crankshaft, which sets off the combustion process in each cylinder. It ensures that the valves open and close at coordinated intervals ensuring they never come into contact with the pistons.

A failing timing belt can result in catastrophic engine damage that requires complete engine replacement. This volatility makes it the most critical maintenance item. Typically auto manufacturers specify the replacement duration for timing belts, often basing it on mileage, every five years or 60,000, whichever comes first.

RELATED: Survival Tips for When Your Car Doesn’t Start in Cold Weather

What is the first thing that one should check if an engine does not start crank?

You can typically hear it from the starter's sound when turning the ignition. If the car is not cranking when you are turning the ignition switch to the start position, you may have a low voltage or a starter problem. If your engine is not cranking, ensure that the car battery is charged and in working order.

What sensors can cause a car not to start?

The most common sensors that will stop your car from starting include the camshaft sensor, the crankshaft sensor, the mass air flow (MAF) sensor, the manifold absolute pressure (MAP) sensor and the throttle position sensor.