What Causes a Diesel Engine to Stop Running?

Driving on the highway or out of town can bring a scary experience- if suddenly your diesel car stalls. Simply put, this means the engine has died. Annoying and causes panic at the same time, if you’re thinking what causes a diesel engine stop running. Then, explore the associated reasons for the regular car maintenance that prevents the occurrence of such instances.

So now, let’s find out what causes a diesel engine to stop running.

What Causes a Diesel Engine Stop Running

So what causes a diesel engine to stop running is hard to diagnose. That’s why most car owners take their vehicles to a nearby maintenance station for examination of the engine. However, with the reasons stated below, now you can diagnose the problem yourself, irrespective of the place. And, with a handy repair kit, you can take a sigh of relief, especially in the middle of a highway. 

1. Damaged diesel injectors

Usually, the diesel injectors fail due to back leakage or overflow. Actually, the main culprits here are the faulty car components. Responsible for overflow and backflow in the system, these worn parts also reduce the rail pressure that halts the diesel engine.

The damaged car components can even obstruct the working of diesel injectors, which further causes low RPM or the engine to stop.

Car diesel engine
The diesel injectors fail due to the back leakage or overflow. (Photo: pinterest.com)

2. Faulty high-pressure pump

The second reason that causes a diesel engine to stop running is the faulty high-pressure pump. The improper functioning of the fuel pump will lead to low pressure in the system. Moreover, with the cracked fuel pump, different types of iron filings can enter the system. This will exacerbate the issue by damaging injectors, which are responsible for fuel injection and ultimately, engine initiation.

3. Insufficient air-fuel supply

The insufficient fuel and air itself speak of the engine-stopping problem. With the crack or any bent in the supply line, you can expect your car’s fuel tank to be blocked by vacuum. By this, the fuel will return to the reservoir and hinder the combustion process.

4. Blocked filters

When the air enters the system, there are filters installed to stop the dirt outside. However, if these air filters are not cleaned or replaced timely, then sufficient air may not reach the system for fuel combustion.

If your beloved car has all the above components working properly, then explore the further reasons that cause a diesel engine to stop running and find the real issue.

5. Damaged relay

The faulty relay will not allow enough heat to be generated for the combustion cycle in the car. Depending on glow plugs, the relay needs to work adequately along with its counterpart for effective diesel engine initiation. So a damaged relay is one of the reasons what causes a diesel engine to stop running.

6. Flat battery

When the battery runs down (especially seen during cold weather), the fuel pump finds it difficult to generate sufficient pressure. As a result, the engine doesn’t start due to the ineffective fuel injection.

car flat battery
When the battery runs down the fuel pump finds it difficult to generate sufficient pressure. (Photo: citizen.co.za)

7. Faulty compression

Low engine compression has a direct impact on heat generation. Subsequently, it hinders the fuel ignition process and causes hard starting.

To diagnose the compression perform a diesel engine compression test. If the meter records the compression reading below the range 20-35 bars or 300-500 PSI, then your car’s engine won’t start.

8 . Bad fuel filter

The fuel cap in the tank is dirty, and the dirt does not allow air to pressure the tank, and your vehicle chokes and dies for lack of required air pressure. Drive the vehicle for an hour or so with no cap on the tank to see if this cures your problem. If it does clean any dirt and congealed grease from the filler cap rubber inner rim.

9 . The car runs out of fuel

Last but not least, your car may run out of fuel which causes the engine to stop running. Check the fuel tank to make sure that your fuel tank is not running out of fuel. If yes, filling it at the station or you can call for help from supportive service or your friends. If you already refill the full tanks, the percentage that your car faces these problems above is really high. At that time, taking your car to the mechanic is the best idea. 

Diesel Engine Runaway

Besides the stop running of diesel engine cars, there is a serious problem which is related to diesel engines which is diesel engine runaway. Diesel engine runaway is a rare condition affecting diesel engines, in which the engine draws extra fuel from an unintended source over speeds at higher and higher RPM and produces up to 10 times the engine’s rated output until destroyed by mechanical failure or bearing seizure through lack of lubrication.

When it comes to diesel engines there’s nothing more horrifying than the idea of a runaway diesel. The engine begins to roar out of control, smoke pours out everywhere, and eventually, the engine will come to a halting stop that will only send shivers down your spine. The whole thing appears and feels like something right out of a horror story. This rare event is something most diesel owners fear, and they’ll want to do anything they can to prevent it from occurring.

Read more:

Knowing how to fix the diesel runaway:

What Should You Do?

What you need to do when your diesel engine stops running is check the fuel tank. Then bring it to a trustful mechanic. They will help to fix the problem and your diesel car will work as normal. The cost of replacing or fixing depends on what you need to replace and what you need to fix. Asking the garage before they make any installments. 

Sum Up

All the above are what causes a diesel engine to stop working. Check it carefully! Finally, after knowing what causes a diesel engine to stop running, you can now avoid the diesel engine stalling by taking certain precautionary steps, which otherwise may get you in trouble. 

Read more about other maintenance tips here to better understand your car and know what to do when it faces any problem.