Freightliner Cranks But Won’t Start? Reasons & Fixes You Should Know!

When your freightliner cranks but won’t start, it could be concerning.

After all, it IS supposed to start when you turn it, right? This is why we investigate this matter and find out why it happens.

Here are some reasons behind this issue and what can be done about it. Let’s get right into it!

freightliner cranks but won't start

Freightliner Cranks But Won’t Start

There are a number of engine issues that may be linked with a truck cranking but failing to start. It could mean that your engine may not be receiving ample fuel supply, or the right compression is not present, or it is basically not getting any fuel at all.

Moreover, the ignition system may also be problematic, as well as the fuel supply system.

But what’s for certain is that this issue has nothing to do with the starting system at all. This is why you should avoid cranking it repeatedly. Otherwise, you may end up causing greater problems to your truck.

For the most part, problems with starting your truck should be resolved by checking important components such as the computer sensors, fuel, starting system parts, fuse, security system, and the battery.

Here are things you need to diagnose if your freightliner cranks but won’t start:

1. Fuel Tank

Before you go through all that trouble of diagnosing complex components of your truck, always start with the fuel tank.

This may seem obvious for some people, but it is also often missed. When the engine is not starting, then it could be that your fuel supply is running empty. This is why it helps to check the fuel tank – even if you see in the fuel gauge that there is some left in there. There are cases when the gauge malfunctions.

With this in mind, you should add more fuel just to make sure the gauge is not showing you the right thing.

2. Inspect your battery.

Once you have checked the fuel and refilled as needed, go ahead and inspect the battery.

Your truck’s battery is what provides initial electric current, which then helps to start your engine. When you have a bad battery, you will never be able to start your engine. Hence, it does not matter how many times you crank your truck – it still would not start.

When your batteries are no longer in good condition, they are unable to hold a charge. There may be corrosions or some loose connections you need to check. This is why you may want to consider giving the battery a jump start at first. If it still does not work, then it may be time to replace it.

3. Check the starting system.

The battery is not the only thing responsible for starting the engine. There are other components that need to be in perfect working condition to get your truck to start. So, go ahead and inspect these things, as well, until you have discovered what the real culprit is.

4. Make sure the security system works.

If you have a modern truck, then it is possible that there are security systems that are not working right. These systems are designed to prevent theft, thus disabling the engine.

In case the security system has gone wrong, or the digital key is malfunctioning, then it would be impossible to start – or even more – the truck. So, you may want to inspect this before you begin searching for a truck repair shop in your area.

5. Make sure the fuse is working well.

Finally, you need to inspect the fuse box and make sure it is perfectly okay. If there is the slightest issue with any of the fuses, your truck may be able to crank but will never start.

Search for the fuse box in your truck by checking the manual. You can also ask your local mechanic to help you locate it, in case you no longer have the manual and cannot figure out where to find the fuse box.

Then, you can search for signs of damage such as loose connections or even a blown fuse that may be preventing you from starting your engine.

As we mentioned earlier, when the truck turns over but won’t start, the problem is more towards the engine itself, not the starting system.

For your engine to work well, it requires a spark at the right time, a specific quantity of fuel, and a certain level of compression in the cylinder.

This section serves as a guidance to troubleshoot the necessary items for a perfectly running engine:

Troubleshooting Guidelines

Now that you have inspected these components, and yet you were not able to start the engine, then it is time to do some troubleshooting.

First, determine if the engine has a spark. You need a spark tester to check the cylinder and to figure out if there is a spark or none at all.

There are different types of testers out there but we recommend getting an adjustable one that can test 10, 30, and 40 KV sparks.

Then, choose a spark plug that you can easily reach and test. Use the tester to test for your 40K spark plug and connect it to the spark wire, as well as the ground tester. As your assistant crank the engine, there needs to be a spark happening at the same time. But if there is none, you will have to conduct a test using the 30 and 10 KV.

But if nothing still happens after doing all of these tests, the spark plug may be the culprit. You need to have these replaced to get your engine to start.

Other possible causes may also include the ignition coil, distributor, igniter, or the ignition module. Thus, you should consider consulting a professional to help you get sorted out and address this issue well.

Read More: What Are Typical Mack Truck Regeneration Problems?

Final Thoughts

When freightliner cranks but won’t start, a multitude of possible issues could be linked with it. If you have conducted tests and inspections, yet failed to get it to start, it is best to seek out professional help from an experienced mechanic who can solve this problem for you.


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