5 Reasons Your Car Won't Start but the Engine Cranks

February 17, 2020

While dealing with a car that won't start is always frustrating, it's even worse when the engine cranks, but the car still doesn't start. Unlike a problem like a dead battery, which usually causes no response at all, the cranking gives you false hope. There are a number of things that could cause this problem, and the best way to find the root of the issue is to bring your Subaru to an authorized dealership service center for a proper diagnosis. You'll find five potential causes of this problem below so you can see how complex the issue is.

5. Empty Gas Tank

Your engine needs fuel, spark, and air to run, and an empty fuel tank means that no fuel is getting to the engine. This isn't always due to people parking a car with the fuel tank needle below the "E." Instead, it may be caused by a problem with the vehicle. A gas tank leak may be to blame, or your fuel gauge may be broken.

4. Faulty Fuel Pump or Relay

Of course, it's not just an empty tank that can keep fuel from getting to the engine. The fuel pump is the component that's responsible for getting gasoline from the tank to the fuel injectors, by way of fuel lines. If the fuel pump isn't working, little or no fuel may be getting through. The pump itself could be the problem; like all mechanical components, these pumps don't last forever. But it could also be that the fuel pump relay is damaged. When our technicians diagnose your vehicle, they'll be able to tell whether the fuel pump needs to be replaced, or if just the relay will need replacement.

3. Failing Battery or Starter Motor

This is a tricky one. A dead battery or a failed starter motor will not allow the engine to crank at all. But these components don't always fail suddenly one day. If a battery is low on energy, or if the connections are loose, your engine may be able to crank, but it may not start--or it may take several tries. Similarly, a starter motor that's beginning to fail may still crank the engine, but won't be powerful enough for it to start. If it's the starter motor, you may hear odd noises in addition to the regular (though extended) cranking.

2. Blown Fuse

Your vehicle is equipped with a number of fuses. These are designed to blow and break the circuit if there's a surge of energy that could damage the components. If there has been a surge, a fuse that controls the fuel pump, the fuel injectors, or another component that's vital for your car's functioning, it may be the cause of your car's failure to start. Unlike most of the other problems, this is one that you can check yourself, if you want. It may still include pulling and checking a number of fuses, but if you find one that has blown, try replacing it and seeing if that solves the problem.

1. Bad Sensors

The computer in your Subaru gets its information from a number of sensors. Sensors that fail to send information to the computer may cause the engine to run less efficiently, and they can sometimes be the cause of an engine that won't start. One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn't working, the spark plugs won't fire, keeping the engine from starting. The same thing can happen with the camshaft position sensor or the throttle position sensor.