4 Causes of a Car Engine That Cranks But Won’t Start

Last Updated on November 21, 2019

Anyone who owns a vehicle has likely experienced the frustrating problem of a car that cranks but doesn’t start, even after repeatedly turning the key in the ignition. However, don’t let desperation keep you from logically figuring out why your vehicle cranks but won’t start normally. 

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Reasons a Car Cranks But Won’t Turn Over

Cranking the car is engaging the starter to energize the engine. The starter causes the flywheel to turn which rotates the crankshaft when all is working correctly. Sometimes this process is interrupted when there is a hitch in the system, and the car engine won’t continue to run after it “turns over” or cranks. 

For the engine to start normally, it requires sufficient fuel pressure, an appropriately timed spark and normal compression. When it doesn’t start, the problem usually lies with one of these systems though the starter system can also be the culprit. Below are some common causes of an engine that cranks but doesn’t start and some troubleshooting tips to identify the cause.

#1 – Spark Problems

Lack of spark may occur due to a damaged ignition module, a faulty crank position sensor, a flooded engine (sometimes happens in older or high-mileage cars), bad spark plugs, or a problem in the ignition circuit, such as the wiring, security system (the fuel flow may have been shut off to prevent theft or the chip in the key could be faulty), or a malfunctioning ignition switch.

An inappropriately timed spark can occur if there’s an issue with the timing system. This can be difficult to diagnose, but a timing light is a useful tool to check that all the cylinders are firing exactly when they are supposed to.

To determine if there is a problem with the spark, visually check the distributor cap (if your vehicle has one) and the spark plug wires, as these may degrade with age. A spark tester should be used to check for a proper arc from each spark plug wire or coil.

If you suspect the engine may be flooded after repeated attempts to start the car, remove the spark plugs and let them dry, then replace them and try again. 

#2 – Lack of Fuel Flow

clogged fuel filter

Problems with fuel flow may be due to a damaged fuse for the fuel pump, a bad fuel pump, contaminated or incorrect fuel in the tank, a faulty or clogged fuel filter or injector, or simply an empty fuel tank (the fuel gauge is not always accurate). 

Having the appropriate fuel pressure is important for your car engine to start or run, especially for fuel-injected engines. Listen to hear the fuel pump buzz for a few seconds as you turn the ignition to the “on” position.

If no buzz is heard from inside the car or back by the fuel tank, the pump may be dead and fuel is not reaching the engine at all.

Note that some fuel pumps only flow while the car is cranking so some cars don’t have an audible buzz. Consult the internet or your owner’s manual for more information for your specific model.

If you do hear the buzz of the fuel pump, you can try putting a flathead screwdriver on top of each injector (with the handle next to your ear) while the car is cranking. If the injectors are firing, you will hear a faint ticking sound from each injector, transmitted by the shaft of the screwdriver.

Some cars have a safety feature called an inertia switch which shuts off the flow of fuel automatically after an impact. If your vehicle recently sustained an impact, check your owner’s manual to see if this feature is present in your vehicle and learn how to manually switch it to allow fuel to flow again.

#3 – Low compression

low compression engine

Each cylinder needs compression for correct engine function. The compression ratio compares the maximum cylinder volume to the minimum cylinder volume during each stroke of the piston. If one or more cylinders have low compression, air from the combustion cycle leaks past the piston rings which limits the amount of work that cylinder can do to spin the crankshaft.

Compression problems can be caused by a broken or loose timing belt or chain or a snapped overhead camshaft. An overheated engine is another severe problem that can prevent your car from starting. 

Try using a compression gauge or tester to see if you have a problem with the compression in your car. If so, a leak down test is a secondary test to check for leaks in the cylinder. A professional mechanic can perform these tests and examine the cylinders if you don’t feel comfortable checking yourself.

#4 – Power Supply Problems

weak car battery

Another possible problem is a weak starter motor that uses a lot of amps to crank the engine, then doesn’t have much juice left to switch on the fuel injectors and ignition system. In this case, you will probably notice that the starter makes an unusual noise when you attempt to crank the engine or it doesn’t turn over at all. 

Weak or corroded battery cables or a dying battery can contribute to the problem as well. Check the voltage of the battery with a multimeter while cranking the engine. It should show over 10 volts. 

Check for blown fuses by visually removing and inspecting the wiring of each fuse when the car is shut off. If they appear to be in good condition, put them back in then try turning the car ignition into the “on” position and using a test light to check each fuse for electrical current flow. Replace any damaged fuses with new ones from an auto supply store. 

Troubleshooting Advice

clean throttle body

If the engine cranks but won’t start, turn the car off and remove the air inlet tube attached to the throttle body. Then spray a small quantity of starting fluid into the engine after gently pushing the throttle open. With that done, try cranking the engine once again. 

If the engine starts but dies after a few seconds, this means that it has no fuel but the spark and compression are okay. However, if the engine does not start, it almost certainly lacks spark.

Avoid repeatedly cranking the car engine to try to make it start, as this can wear out the starter or drain the battery.

If you must try multiple times, wait several minutes for every 15 seconds of cranking performed to allow the starter to cool down. It shouldn’t take more than a couple seconds per attempt to know if you’ve resolved the issue.

Checking sensors and actuators for problems is critical, as modern cars have a variety of electrical components that can cause failure in the engine starting process.

The best way to do this is to check the car computer for codes (faults in the electrical system) with a scan tool that can be found at most auto supply stores. Most of these problems will also cause the check engine light to illuminate, but not all of them. 

 

Comments

  1. Can I still drive my Isuzu rodeo 2004 when the immobilizer light comes on? Sometimes it won’t start I take the key out and put the key back in several times and it does start. But is it dangerous to drive it after that?

    Reply
    • It’s not dangerous per say while driving, but you run the risk of not being able to start it when you are away from home. Definitely something you should get taken care of so you don’t have to stress every time you try starting it.

      Reply
  2. I have a VW Crafter 2006. My key broke off in the ignition. A locksmith removed the broken key and cut a new key. With the new key the engine cranks but don’t start. Should I replace the whole ignition.

    Reply
    • It shouldn’t have anything to do with the key so I wouldn’t just replace the entire ignition system. You need to determine whether the problem is fuel, spark, or compression related.

      If you feel comfortable, you can test for spark by removing a plug wire, inserting a long screwdriver into the plug wire boot, and placing the end near the engine block. Have another person crank the engine and look for a spark. If there is a spark, the issue is likely fuel related.

      Reply
    • Have the new key programmed to PCM and security system that’s why it doesnt start it’s not recognized by PCM or security so it wont start until it is immobilizer in sec system is shutting down its start capabilities right now had same problem with a focus I had lost key had new one made it was transponder key and was programmed at locksmith to PCM but only specific makes dealer can program it to sec system though hope this helps

      Reply
      • You can programme keys to your car yourself on my focus you turn it so many times lock doors manually etc then press unlock on the key and it’s programmed into that specific car. Saves some money .

        Reply
  3. What if when you put the key in the ignition (Honda civic 2009 exl) the security light does not turn on. I mean not even blink it never turns on I don’t even know what color is it. Every other light turns on but the security light. And my car is just rolling over and just wouldn’t start.

    Reply
  4. So I do have a 4runner 1997, 4cyl and 2.7 engine that don’t want to starts. It crank and swing but wont start. The fuel filter and the fuel pump have been change, the crank sensor also change, the testing to see if there is any sparks from the spark plug wire. But it still won’t start. what could be the problem?

    Reply
  5. I have a 2007 Ford Ranger with a 2.3l engine. My problem I’m having is it cranks fine but starts real hard when cold or letting it sit over night after running it. I’ve changed plugs and wires,throttle position sensor,massive air flow sensor and fuel filter. I have no codes and the check engine light is off. The only thing I haven’t changed is the fuel pump. It runs great after it starts. I can shut it off after running a minute or so, and it will start right back up. It idles around 850 to 900 rpms when warm. It has plenty of power when I drive it. It doesn’t hesitate or miss when I run it. I check the oil once a week and fine no signs of antifreeze in the oil. I do hear the fuel pump cycle when I turn the key on. The truck has on 85,452 miles on it. Not to brag, but it has no rust on it. I’m about to get rid of it because I can’t figure it out. Can anyone give me more idea’s of what it can be. I should check the fuel pressure but I don’t have a fuel gauge to use. I know a lot of people will say it’s a Ford LOL. It would make me happy if someone could lead me in the right direction on what could be wrong with it.

    Reply
  6. 2006 Mercedes E350: 1. It may start right away 2. It takes several attempts to get it started. 3. It starts after you leave it for some time. The fuel pump, crank and cam shaft Sensors have been changed but the problem remains. How can I resolve the problem? Please help!!!

    Reply
  7. 2015 kia soul spin bearing and rebuild engine crank and not starting, was getting that kick to start sound but after scan and erase a trottle/ pedal sensor code that was found no longer getting that kick to start sound. Anyone can help?

    Reply
  8. I have a 2013 Hyundai Elantra it turn over but won’t stay on I changed the starter and spark plugs but it still won’t start.

    Reply
  9. Hi I have 08 Mitsubishi Lancer and I charge oil and filter and the after that the car doesn’t want to start a crank but weak can someone help me I check every single fuse and nothing and a check if the is a cable lose and nothing I trying a new fuel pump to see if this is the problem

    Reply
    • It sounds like there’s something else going on here. Perhaps something was bumped while you were changing the engine oil and filter? Make sure the battery terminals are tight. Changing the engine oil and filter should not affect the vehicle’s ability to crank and start.

      Reply
  10. hello. i have a 99 nissan truck. The engine blew. i swapped engines only the longblock. everything else is original that i put back in. Now it cranks but no start. I checked everything including distributor spark plugs battery ground cable fuses.etc etc. still no start but it acts like it wants to start. What do u think?

    Reply
    • Check to make sure everything is plugged in. Check ground straps too. Any codes?

      Old wiring that’s been disturbed could’ve caused an open circuit somewhere. First thing I’d do if I had no codes would be to poke around the engine bay with a multimeter to make sure I was getting the expected voltages to each of the sensors.

      Reply
  11. 2013 renualt trafic diesel 2 litre customer left ignition on for 30 mins switched off went to start turns over wont fire.cam and crank sensor codes so fitted new sensors still no start.found if you unplug the cam sensor and the airflow sensor vehicle starts revs and runs you can plug the cam sensor back in while running seems ok but when you 0lug airflow sensor back in vehicle stops.will only restart when both sensors are unplugged.tried to get wiring diagram for cam / airflow sensor renualt in australia are not intrested unless they charge and check vehicle themselves no one seems to have info as renualts not a big seller in aus

    Reply
  12. I have Opel Vauxhall 1996 1.4i. The car cranks but does not start. I had the cambelt and water pump changed. However if I spray starting liquid into the air box it starts immediately but engine light remains on. What could be the issue here.

    Reply
    • Scan the codes first, as they will help you narrow down the problem.

      If it starts with starter fluid it’s probably a fueling issue. You know it has air and spark because it was able to start at all, then you introduced some fuel with the spray. I would approach the problem in this order:

      Check fuses and relays. Could it simply be a bad fuel pump relay?

      Take a look at your injectors. Are they all plugged in?

      Perform a fuel pressure test.

      Reply
  13. I was driving my car down the road it got over heated notice that someone more likely put a screwdriver hole in my hose for my radator so now the coolant leaked all out. it got over heated so i pulled over and when i did i had a hard time starting it back up finally got it started back up when i did i was only able to drive it for like 4 minuets then the car turned off on me completely i got it off the road tried to restart it and it would crank over but it would not turn over after a few times of doing that it decided to make a big knock now i cant get nothing what will that be and how can i go about fixing the issue thank you

    Reply
    • You shouldn’t drive a car without coolant. Since you overheated the engine and tried to drive it, any number of things could be wrong. I’d take it to a shop you trust and tell them what happened, then go from there with their diagnosis.

      Reply
    • A car needs fuel, air, spark, and compression to run. You’re missing at least one of these. One of the easiest things to check for is spark. Are your spark plugs firing? You could perform a fuel pressure test to check for adequate fuel pressure, and a compression test to check compression. If your car won’t even fire, it’s likely not a problem with air.

      You could have a bad sensor or timing issue (the latter affecting compression) as well.

      Reply

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