Diesel Car Won’t Start? 6 Solutions (Easy Fix)

If you have a diesel-engine vehicle, check out the most common reasons your vehicle won’t start and how to solve the problem.

Many problems with diesel-engine vehicles not starting can be handled quickly and easily.

Most Common Reason Your Diesel Vehicle Won’t Start

The most common reason is that the battery is dead.

Check also our article about why a car won’t start if the battery works.

If the battery is dead, you’ll want to investigate to see if there is a simple cause of the dead battery, like leaving your lights on for an extended period of time.

Once you’ve identified the problem, you can have the vehicle’s battery jumped to see if that solves the problem.

If the vehicle starts after having the battery jumped, your problem may be over.

However, if your battery goes dead again in the next few days or hours, you may need to investigate the vehicle’s alternator.

#1 Corroded Battery Terminals

If you suspect the battery, but the voltage on the battery seems good, it might be a problem with the battery’s terminals.

If this is the case, you’ll need to check the battery’s terminals.

When you do this, you’re looking specifically where the battery wires connect to the battery itself. First check to make sure the vehicle is off.

Check each terminal to ensure it is connected properly.

Sometimes, connections can come loose. Next, check for any corrosion on the battery terminal.

If there is corrosion around the battery terminals it could prevent the battery from working properly.

In this situation, you’ll want to clear the erosion from the terminals and reconnect the battery terminals:


#2 Bad Diesel Fuel Delivery

Another issue that could cause a diesel vehicle not to start is bad fuel delivery.

The main culprit behind this problem is air in the fuel. If the diesel vehicle started and then died shortly after starting, it’s a good chance there’s air in the fuel.

Air can get into the fuel through leaks in the fuel lines or through a faulty fuel pump. Check both of these areas to determine what needs to be replaced.

#3 Dirty Diesel Fuel Filters

Diesel vehicle fuel filters should be maintained on a regular basis. Most automotive technicians recommend the fuel filters be replaced every 20,000 to 40,000 miles.

After time, dirty fuel filters can get clogged with debris, which interrupts the filtering process.

If you suspect a clogged fuel filter isn’t allowing your vehicle to start properly, it’s a good idea to change the fuel filter before making any other expensive repairs to see if it solves your vehicle’s problems.

Make sure to check this on diesel cars as it can cause problems (also for low-mileage diesel cars)

#4 Contaminated Diesel Fuel

Unlike unleaded and premium fuel, diesel fuel isn’t as clean. It’s a dirty fuel type that is prone to bacteria.

When the weather is warm, bacteria in diesel fuel can grow quickly and gum up your vehicle’s fuel delivery system. Two signs to look for if your vehicle isn’t starting and you suspect contaminated gas is a foul or sulfuric smell coming from the vehicle, or black or green gunk in the fuel tank.

If contaminated diesel fuel is preventing your vehicle from starting, you’ll need to drain and clean the diesel fuel tank.

It’s important to examine the fuel pump and fuel lines at this time too. If the pump or lines show any signs of gunk from contaminated gas, you should clean those areas as well.

#5 Diesel Car Won’t Start in Cold Weather

When the temperatures are low and the weather is frigid, your diesel vehicle may have a hard time getting started.

This is true with all vehicles, but diesel vehicles are more prone to problems starting in frigid weather because of the way they are designed.

If it’s cold and your diesel vehicle doesn’t start, it might be related to cold weather and freezing temperatures.

Try to Reduce Battery Usage in Cold Weather

Your vehicle only has a designated amount of battery available on any day of the year.

Diesel vehicles are already prone to problems with starting during cold weather, so it’s best to eliminate as much unneeded battery usage as possible.

To do this, unplug any car chargers you are using.

Try to turn off the radio, decrease the amount of heat used inside the cabin, and turn off any unnecessary lights.

Not only is this important to do when driving the vehicle, it’s also important to do it every time you shut the vehicle off as well.

Giving your diesel-fueled vehicle the opportunity to draw as much power as needed to run the vehicle from the battery is ideal to prevent the vehicle from not starting in cold weather.

#6 Choose the Right Diesel Fuel

Did you know there are two types of diesel fuel?

There are. Diesel #1 and Diesel #2.

Diesel #2 is recommended by major automotive manufacturers as the preferred diesel for driving conditions.

If you fill up your diesel vehicle at a traditional gas station, you will likely only have one diesel option, and that will be diesel #2.

However, if there is more than one diesel option, you need to make sure you choose the right option.

Diesel #1 is much more volatile than diesel #2 and not recommended for regular diesel vehicles.

If you accidentally fill your diesel vehicle with diesel #1, you may experience rough driving conditions, or find your vehicle unable to start.

If this happens, the fuel tank will need to be drained and cleaned.

After draining the tank and making sure all of the volatile diesel is out of the fuel lines and pump, you’ll want to fill it with the correct diesel. It’s also important to make sure the fuel filters weren’t compromised as well.

Give Your Diesel Vehicle Time to Warm Up

Sometimes, you just have to jump in your car or truck and take off.

But, if you can, you should try to avoid this habit. Especially during cold weather months. When a diesel vehicle is driven and hasn’t had time to warm up, it’s hard on the vehicle.

The harsh weather and cold engine put lots of wear on the engine, camshaft, and other internal parts.

Eventually, this bad habit could cause expensive damage that could leave you stuck with a vehicle that suddenly won’t start.

Most diesel engine vehicles don’t need long to get warmed up after starting. Most vehicles are pretty well warmed up in about five minutes.

Store Diesel-Engine Vehicle in a Heated Location

To provide even better performance from your diesel vehicle in cold and winter months, you should store the car in a heated location.

Not only will this allow your vehicle to get warmer quicker, it will also help decrease the wear and tear on the vehicle’s other components including the glow plugs.

Final Thoughts

If you suddenly discover your diesel vehicle won’t start, you shouldn’t panic.

There are several relatively easy and cheap ways to diagnose the issue and determine what to do next.

It’s important to rule out the simplest reasons your vehicle isn’t starting and then move on to more difficult issues as needed. Since a dead battery is the number one reason any car won’t start, it should be the first thing you consider.

If you think it’s the battery, make sure to inspect the battery for any damage, and then try to jump it. Only after you’ve done this step should you consider other things on the list.

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