If your car won’t start but the battery is good, there are a number of components that can cause this and you will need to troubleshoot it and find the problem. This may be a bit tricky since there are tons of components in a car that has to work together. If one component fails, then your car won’t start, let alone run properly. But don’t worry, we’ll guide you on how to troubleshoot your car if it won’t start. You should be able to find the cause by the end of this post and you’ll know how to fix the problem.
- Troubleshooting: If the engine doesn’t crank
- Troubleshooting: If the engine still cranks
- Repair cost estimates
Car Won’t Start but Battery is Good: If the Engine Doesn’t Crank
There may be some confusion about the terms, so let us clear it first. Some people mistake the term “turn over” as the engine turning on. So when they say that their car won’t turn over, they mean the engine won’t turn on. However, many car mechanics use this term when they’re referring to whether or not the engine cranks. So when mechanics say “turn over”, they’re talking about whether or not the engine is cranking.
Simply put, “turning over” means the engine cranks. If you hear your engine turning on its starter and moving the crankshaft, then it’s turning over. But if it doesn’t run after that, then the engine is turning over but won’t turn on. Hopefully, that clears up the confusion over the term.
Now, when a car won’t start there are two scenarios: the engine cranking and not cranking at all. What do you do if the engine doesn’t crank at all? Well, here are the things that you should check:
Verify the Battery’s Condition
If you turn the ignition to “ACC” and see the lights in your car and other accessories come on, this means the battery still has charge. However, you will need to check whether or not your battery is dying. Your car’s battery may still be holding very little charge that’s enough to power the accessories, but not enough to actually crank the car. Most accessories in a car require little electricity, but the car’s starter motor requires around 300 amps to start. If your battery is dying, then it can’t power the starter motor.
The first thing you should do is check the physical condition of your battery. You may have corroded battery terminals, in which case you will need to clean up with sandpaper since they can disrupt your battery’s ability to transfer electricity. However, a surefire way to check your battery’s condition is with a multimeter. Here’s how to do it:
- Locate your car’s battery. Remove any pieces of jewelry you have and make sure you’re working in a dry area.
- Set your multimeter to the 20 volts setting.
- Connect the multimeter’s red probe to the positive terminal and the black probe to the negative terminal.
- The multimeter will immediately take a reading. If it’s under 12.6 volts, then you have a bad battery and you will need to change it.
This video from ChrisFix will give you a great visual guide on how to test a car battery:
To learn more about testing car batteries, you can read our article here.
Car Won’t Start but Battery is Good: Check the Fuses and Ignition Switch
If the battery is in good shape and still has enough charge, then the next things you should check are the fuses and the ignition switch. Check your owner’s manual to see the location of the fuse box. After you locate it, see if there is fuse or metal wire damage. If the fuse or the metal wires inside it has damage, then that may be the cause for your car refusing to crank. In this case, you will need to replace the fuse. Most common fuses are around $20 to replace, but some might cost up to $100 to replace.
If the fuses are fine, then the next thing you will check is the ignition switch. However, this may be a bit more difficult to diagnose. The ignition switch is an electrical switch inside the key housing that touches your key. When you turn your car key, the switch will turn on, allowing an electrical current to run through the car. This affects all the electrical components in the car and maybe the reason why your car won’t start even though the battery is fine.
When the ignition switch is bad or failing, you will notice irregularities with the car when you turn the key. For example, your car may refuse to turn on the accessories entirely even though the battery is fine. It might also refuse to switch off even if you turn the key off and pull it out. Additionally, if you’ve been driving and the engine suddenly shuts off, this could also be a sign of a bad ignition switch. If you see the symptoms above, then you will need to check the ignition switch and replace them.
Car Won’t Start but Battery is Good: Check the Starter Motor
Another common reason why your car won’t start even though the battery is fine is a faulty starter motor. This is usually the culprit when your car’s electronic accessories are fine but the car is refusing to crank. The starter motor is an electrical motor that rotates or cranks your engine by providing torque. Once your engine turns and begins the combustion process, it will run on its own and you can turn off the starter motor – provided there are no issues with the ignition system and combustion process.
Some common symptoms of a faulty starter motor include grinding noises when you turn the key and the starter staying on even after the engine is on and you let the key go. Freewheeling is also a common symptom, this is when you turn the key to crank the car but all you hear is a whining noise. This means a pinion gear inside the starter has worn out and it’s spinning freely but it’s not actually engaging the engine’s flywheel because of the worn-out gear, hence why it’s called freewheeling.
You can diagnose this by listening for the sound your starter motor makes. First, have someone else crank the car for you. Then open the engine bay and listen for the noises your starter motor makes. If you hear a repeated clicking noise, then the starter motor should be working just fine. However, if you only hear a single click or no clicks at all, then you may have a bad solenoid on the starter. You can check the starter solenoid by using a voltmeter, here’s a quick guide on how to do that:
Checking the Starter Motor’s Solenoid
- Place the positive lead from the voltmeter on the lower terminal of the solenoid. Then, place the negative lead on the upper terminal.
- As you’re doing the first step, have someone else turn the ignition key. Ensure that the leads are firmly touching or attached to the solenoid’s terminals to get an accurate reading.
- Pay attention to the voltage drop that is shown on the voltmeter, you should see a drop of 0.5 volts.
If the drop is less than 0.5 volts, then that means there’s a problem with the solenoid. Meanwhile, if the drop is higher than 0.5 volts then there might be a problem with the connection, such as a crimped line from the battery to the solenoid.
This test can be complicated and quite dangerous to perform on. If you’re not sure about your own mechanical skills, then you should take the car to a repair shop and ask a mechanic to do the diagnosis. If you have a bad starter motor, then you will need to replace it with a new one.
And that’s it, those are the things that you need to check if your car won’t even crank. However, if the car cranks and the battery is fine but it will not start, there are different things that you will need to check. This segues us perfectly into our next section:
Car Won’t Start but Battery is Good: If the Engine Cranks
We’ll say this from the start: troubleshooting an engine that cranks but won’t start is going to be more difficult and time-consuming. However, we aim to make that easier for you and we’re going to guide you through these hard and trying times. Anyway, a cranking engine means that the battery and other electrical components are working fine. So you can scratch the battery, the ignition switch, and the starter from the list. Here are the things you need to check:
Car Won’t Start but Battery is Good: Is Your Car Out of Gas?
Yes, it can be as simple as this. When was the last time you filled up your car? Most people won’t forget to fill up their car with their gas as they have a fuel gauge telling them their fuel levels. However, your fuel gauge may display an incorrect reading, where the gauge is indicating the car still has fuel but has actually run out. For example, certain model years of the Nissan Rogue had this issue. It was quite a common problem with the car and many customers complained about it.
Unfortunately, most modern cars now have a fuel float mechanism that supports the sending unit. This prevents you from checking your fuel level with a dipstick. However, if you’re sure that you’ve filled up your car with gas recently and haven’t run out, then something else is preventing your car from turning on.
In any case, if you believe that your fuel gauge is giving you incorrect readings or is behaving erratically, then you should check and fix it. You can diagnose it yourself or take it to your trusted mechanic.
Bad Fuel Pump or Fuel Lines
A fuel pump, as the name suggests, is responsible for pumping fuel to your fuel injectors and then into your engine. The fuel pump can wear out over time, usually after about 200,000 miles for most cars. However, it can fail at 100,000 miles or even earlier if the car isn’t properly maintained. If your fuel pump has gone bad, then it won’t be able to pump fuel into the engine. If your car has done more than 200,000 miles or you haven’t checked your fuel system lately, then you may have a fuel pump issue.
To check this, simply turn your key to the ‘ACC’ position to turn on the fuel pump. If you hear a hum from the back of the car, this means your fuel pump is running just fine. If it is, check for fuel leaks beneath the car. Your fuel line may be damaged and the engine isn’t getting enough fuel to start itself. If you don’t hear the fuel pump working, then you should check the fuel pump fuse and voltage. This might be the reason why your fuel pump isn’t functioning.
Additionally, if you live in colder areas, your fuel may freeze and isn’t flowing into your engine. In this case, the fuel system needs to thaw out first before you can start the car. To prevent this in the future, park your car indoors if possible so it’s less exposed to cold weather. If you have no choice but to park it outside, try not to leave it off for too long and turn it on every once in a while to prevent the fuel lines from freezing.
Check the Fuel Pressure and Injectors
Next, you’ll want to check the fuel pressure and you will need a fuel pressure gauge, which should cost you no more than $30. The steps to check your fuel pressure are as follows:
- Connect your fuel pressure gauge to the Schrader valve.
- Turn your key to the “ON” position, this will turn on the fuel pump.
- Your fuel pressure gauge should read 40 – 45psi. If it’s less than that, you will need to check the fuel pressure regulator and the fuel filter as well.
If the fuel pressure is fine, then the next thing you need to check is the fuel injectors. Ideally, you should use a mechanic’s stethoscope, but you can always use a screwdriver instead. To check the fuel injectors, locate the injectors, and then touch the screwdriver against the fuel injector. On the other end of the screwdriver, press your ear against it and have a friend crank the engine. If you hear a rhythmic clicking as the engine is cranking, then that means the fuel injectors are firing fine. Repeat this process on all of the fuel injectors to ensure that they’re all working.
Check the Spark Plugs
To check the spark plugs, you will need a multimeter. We prefer to start by checking the spark plugs before the ignition coil, which means you will need to remove the spark plugs from the engine. Once removed, use the multimeter to test the resistance of the spark plugs. Here’s how to test a spark plug:
If the spark plugs are bad, then you will need to replace them. They should cost no more than $20 each to replace, but you should replace the entire set altogether. However, if they’re good, then it’s time to test the ignition coil.
Check the Ignition Coil
The best way to test the ignition coil is by doing a spark test. This test will determine whether or not the ignition coil is transferring enough electricity to create a spark, which is essential to the combustion process. The process will differ depending on which type of ignition coil you have in your car. If you have a coil-on-plug system, which most modern cars have, here’s how to do it with a coil-on-plug spark tester:
RockAuto Auto Parts made a great quick video on how to test a coil-on-plug system:
We’ve written a comprehensive guide about ignition coils, from how they work, diagnosis, and replacement cost. You should read it if you’d like to learn more about ignition coils. However, if your coils are fine, then it’s time to continue our troubleshooting and check other components.
Testing the Engine Compression
The next thing you want to check is your engine’s compression. You will need a compression tester to do this, which you can either buy or rent at an automotive parts store. Here’s how you do a compression test:
- Remove all of your ignition coils (or spark plug cable if you have a distributor-type coil) and all of your spark plugs.
- Insert the compression tester’s hose into the spark plug hole.
- Ask a friend to crank the car four times while completely flooring the accelerator pedal.
- Repeat steps 2 and 3 on each cylinder.
If the compression gauge/tester registers 90psi, then your cylinder has a healthy compression. If it’s below that, then there are a variety of issues that may cause this. Such as bad piston rings, a bad valve, or a crack on your engine. Identifying the exact cause can be tricky, so we recommend taking your car to your trusted mechanic for a diagnosis.
If your car won’t start but the battery is good and it still cranks, those are the things that you should check. There are a few more things to check such as the air intake system and the ignition timing. We recommend watching this video from ChrisFix to give you a visual guide on how to diagnose the car:
Car Won’t Start but Battery is Good: Repair Cost Estimates
Since there are many possible reasons why your car won’t start even though the battery is fine, the repair cost varies as well depending on what the exact problem is. They can range from $100 to even $2000. Here are some rough estimates and the cost you can expect to pay depending on the problem:
Ignition Switch Replacement Cost
If you’ve verified that the problem is the ignition switch, you will need around $250 to replace the ignition switch. $150 for the part, and another $100 for the labor cost. However, this is the highest estimate so it may be cheaper for certain cars. Needless to say, luxury cars are likely to cost more than $250.
Starter Motor Replacement Cost
The cost to replace a car’s starter motor will vary depending on your car’s make and model. To give you a rough estimate, most cars will cost you around $180 – $300 for a starter motor kit, excluding the labor cost. Needless to say, if you have a luxury or exotic car it will cost you more. For example, a starter motor kit for some Mercedes-Benz models is anywhere between $400 – $800. As for the labor cost, it’s usually between $50 – $100 per hour.
Keep in mind that these are rough estimates and just for your starter motor. If your flywheel has been damaged, it can lead to more repairs and higher costs. Which could bring your total repair cost to around $1500, depending on your car make and model. This is why you shouldn’t ignore grinding noises when you start the car, as they could damage your flywheel.
Ignition Coil and Spark Plug Replacement
These replacement jobs are among the cheapest on this list. Ignition coils usually cost around $300 to buy. While the labor cost is usually around $150, which brings your total ignition coil replacement cost to about $450. Spark plugs are even cheaper, they’re usually no more than $50 for an entire set. While labor costs will vary between $40 – $100, which brings your total to around $150.
If you have the tools, we recommend doing these two replacement jobs yourself so you don’t have to pay for the labor cost. Our article about coil packs also contains guides on how to diagnose and do the replacement job for both the coils and spark plugs yourself, so you should read that if you’re planning to do the job yourself.
Fuel Pump, Filter, or Injector Replacement
If you have an issue with the fuel pressure, chances are either the pump, the filter, or the injector is the culprit. A fuel pump is typically around $800 to replace including labor cost. While the fuel filter will normally set you back around $150 or so to replace. The fuel injector is the most expensive one here, as the cost can be as high as $1,200 depending on your car’s make and model. The labor is actually relatively cheap, at around $200 – $250, but the cost of the fuel injector itself usually already starts at $600.
Air Intake Issues
As the video from ChrisFix showed, your car may have issues with the air intake system that’s preventing the car from turning on. If the issue is just a dirty air filter, then replacing it should cost no more than $80 for most cars. However, if you have a faulty Mass Air Flow sensor (MAF), then you might be looking at a $400 bill, but this already includes labor. If the issue lies with your intake manifold, then replacing it will set you back between $400 – $600 including labor.
Compression Loss: Repair Cost Estimates
This is where it gets scary for your bank account. Compression loss is caused either by something not operating properly or damage to your engine’s internals. As mentioned, this includes bad piston rings, bad valves, blown head gasket, and several other possible reasons. The parts cost for most of these parts are not too expensive, but the labor cost is likely to be significantly higher than most other replacement jobs.
The reason is that these parts are the internals of your engine, and replacing them will require your mechanic to dismantle a significant portion of your engine. For example, to replace a blown head gasket, your mechanic will need to do the following:
- Drain all oil and coolant from your engine.
- Remove a significant portion of your engine, including the camshafts, cylinder heads, and the broken head gasket itself.
- Clean the surface of the engine block and bolt holes.
- Fit in the new head gaskets, the cylinder heads, and everything else that was taken apart before.
- Set the camshafts and timing gears back to your car’s exact orientation, making sure it runs smoothly as it should.
As you can see, it’s a long and tedious process that can take a couple of days or more to finish. This is why a head gasket replacement job can be as high as $2,000. While a head gasket set is usually no more than $500, the labor cost can be as high as $1,500. Often times you will need an engine rebuild, which can cost anywhere between $1,500 to $4,000 depending on your vehicle’s make and model.
Ignition Timing Adjustment Cost
Your car uses a timing belt to make sure the camshaft and the crankshaft are in sync. When they aren’t in sync, then the cylinders won’t fire correctly and your engine won’t run. Sometimes, the timing may be off simply because the timing belt was a bit loose, which causes the camshaft gear to skip teeth, throwing the timing off. If this is the case, you can watch the video from ChrisFix to diagnose and fix the issue. However, if you don’t feel like doing it yourself then a mechanic will usually charge you $70 to readjust the ignition timing.
Car Won’t Start but Battery is Fine: Wrap Up
Diagnosing a car that won’t start even though the battery is fine can be tricky. The car has tons of components, mechanical and electrical, that work together to ensure the engine can turn on and run smoothly. Hopefully, this article has guided you on how to troubleshoot the problem and helped you find a solution.