If you are wondering why your car dies when you put it in gear, or why your car dies when you put it in reverse, I might have some information for you. There are quite some problems that can cause your car to shut off while driving and then not start. Here are some:
Key Takeaway
Why Did My Car Shut Off While Driving And Won’t Start?
- Failed fuel pump
- Failed alternator
- Bad main relay
- Failed crankshaft and camshaft sensor
- Oil in spark plug tube
- Broken timing belt
- Broken timing chain
Why Did My Car Shut Off While Driving And Won’t Start?
Your car could be completely fine and the next moment it could shut off while driving and won’t start again. Some car parts show signs before they fail, and some don’t. So, if your car shut off while driving and won’t start again, here are 7 possible causes:
1. Failed fuel pump
A failed fuel pump will not deliver any fuel to the engine and your car won’t be able to start. A great way to see if the fuel pump is the problem is by checking the pressure at the fuel rail. You will need a fuel pressure test gauge
(check prices on amazon.com). The ideal fuel pressure should be between 30 and 50 PSI depending on your vehicle specification.
In addition, a properly working fuel pump should make a buzzing noise when you start your engine, or in this case when you crank it. So, remove the gas cap and have someone standing by and listening for a buzzing noise as you turn the ignition key to the on position. If there is a buzzing noise, the fuel pump is working and the reason why your car shut off while driving and won’t start now is because of something else.
2. Failed alternator
A faulty or failed alternator will result in your vehicle completely shutting off while driving and you won’t be able to start it. A failing alternator usually shows signs before completely failing. A decrease in power is noticeable, followed by vehicle electronic failures such as headlights starting to dim and the radio starting to fade.
Once the vehicle voltage drops under a certain level, a battery light will be illuminated on the dashboard. Sometimes a failing alternator makes a whining or growling noise which you can notice if you open the hood and listen carefully. You should check the alternator with a voltmeter (check price on amazon.com). A good working alternator should produce at least 13.5 volts. Also, while you are at it, check the serpentine belt. If the serpentine belt is broken, it won’t spin the alternator and your car won’t have any power.
3. Bad main relay
The main relay controls power to the fuel and other electronic systems. If the main relay fails, many electronic components of the vehicle won’t work. One of those is the fuel pump. Without the fuel pump, there won’t be any fuel going from the fuel tank into the engine and your car will shut off while driving and you won’t be able to start it again.
4. Failed crankshaft and camshaft sensor
A failed crankshaft sensor will cause the vehicle to immediately turn off due to no timing signal. The crankshaft sensor determines the position and the rotation speed of the crank and sends the signal and timing position to the computer.
5. Oil in spark plug tube
If the spark plug tube seal wears off, it can get contaminated with oil and that particular spark plug won’t be able to receive power and your vehicle will shut off while driving and you won’t be able to start it.
If this is the case, you should replace the valve cover gasket and tube seal. A new spark plug might be needed as well.
6. Broken timing belt
The timing belt can slip off, jump teeth on the camshaft sprocket, or break. If this happens, your vehicle will shut off immediately and you won’t be able to start it. The timing belt has a function to synchronize the rotation of the crankshaft and the camshaft. Without a proper working timing belt, the engine valves won’t open and close at the correct time and the engine will shut off.
If this is the case, a new timing belt should be installed. While you are at it, check the timing belt tensioners as they can also get loose over time.
7. Broken timing chain
A broken timing chain will result in a car shutting off while driving. A timing chain can stretch and jump teeth on the camshaft sprocket. The timing guide can break off causing clocking noise.
Related Questions
Why does my car die when I take the gas cap off? If you take the gas cap off and drive your car, it could shut off after driving for some time. This is because a vacuum builds up inside the fuel tank and the air gets sucked into the fuel system causing your car to die. You should be able to get a check engine light if there is an issue with your gas cap.
Why does my car die when I turn the ac on? Your car dies when you turn the AC on because by switching the AC on, you are requesting more power from the alternator. If the alternator is bad and about to fail, he won’t be able to generate enough power and will fail completely. This means that your car battery will no longer be recharged and as soon as it drains completely, the car will shut off.
Can bad spark plugs cause a car to shut off while driving? Bad spark plugs can cause a car to shut off while driving. A spark plug has a function to ignite the air/fuel mixture in the combustion chamber. If for some reason the spark plug is faulty or contaminated by oil, it won’t be able to ignite the mixture and no combustion will occur resulting in your car shutting off while driving.
Can a dead battery cause a car to die while driving? If your car has a dead battery, you won’t be able to start the vehicle, to begin with. But, if your alternator fails while driving, the battery won’t get recharged and when it gets completely drained, the vehicle will die while driving. The battery has a function to supply the electric current needed to start the engine and to run smoothly.
