The Causes of Diesel Engine Car Losing Power When Accelerating

In this article, we will examine some common causes of diesel losing power when accelerating and explore potential solutions to rectify them!

An automobile’s engine generates power by combining air and fuel to initiate combustion. The energy generated from this combustion is subsequently transmitted to the vehicle’s wheels, propelling the car forward.

The engine’s primary role is to consistently execute this process with optimal efficiency. Nonetheless, for various reasons, the engine may lose power, resulting in diminished performance.

Reasons Why Diesel Cars Losing Power When Accelerating

Defective Fuel Filter

The fuel filter plays a crucial role in screening fuel before it enters the engine. When the fuel filter becomes clogged, it impedes the flow of fuel to the engine, causing a decrease in engine performance. You may notice a lack of power during acceleration and occasional jerking.

To address this issue, locate the fuel filter, which can be found in the engine bay or near the fuel tank in your car’s trunk. If you possess the necessary skills, replace the clogged fuel filter yourself, or take your vehicle to a local mechanic for replacement.

Blocked Air Filter

For proper engine function, clean air is essential. If dust and other particles infiltrate the combustion chamber, it can lead to engine damage.

To ensure the continuous flow of clean air to the engine, an air filter is utilized. However, this filter becomes ineffective after approximately 15,000 to 30,000 miles, depending on driving conditions.

Neglecting to replace the air filter as needed will result in a noticeable decline in your car’s performance.

Obstructed Exhaust System

The exhaust system’s role is to expel harmful and unnecessary gasses from the engine. The faster these gasses are expelled, the sooner the engine can initiate combustion, resulting in increased engine power.

Conversely, obstructions such as a restrictive catalytic converter or a clogged exhaust hinder engine performance.

While aftermarket cleaners can address clogged catalytic converters, using a quality fuel system additive every 3,000 miles can help reduce the contaminants that lead to clogging in the first place, eliminating the need for unclogging.

MAF Sensor Dysfunction

The Mass Airflow Sensor (MAF) measures the required air intake for acceleration. 

It relays this measurement to the Engine Control Unit (ECU), which adjusts the throttle accordingly. A malfunctioning MAF that inaccurately measures airflow can lead to a significant power loss. 

These sensors can deteriorate due to heat and dust accumulation. Regularly cleaning them with specialized products can enhance their functionality and, consequently, the engine’s efficiency.

Oxygen Sensor Malfunction

While the MAF measures incoming air, the Oxygen sensor gauges the gasses exiting the engine. It is typically located in the exhaust pipe. When the MAF readings align with the Oxygen sensor readings, it indicates your car is running smoothly.

The oxygen sensor also impacts the fuel injection system, making its proper operation crucial for your car’s performance. 

A malfunctioning oxygen sensor can result in a rich air-fuel mixture, adversely affecting fuel economy. Fortunately, replacing this sensor is relatively inexpensive and straightforward.

Carbon Buildup on Fuel Injectors

Fuel injectors play a vital role in introducing fuel into the combustion chamber under high pressure, similar to a spray. 

Precise fuel delivery is essential for proper combustion, as even a slight miscalculation can disrupt the combustion cycle, leading to power loss or, in extreme cases, damaged pistons.

Carbon buildup, often caused by low-quality fuel, can obstruct the injectors’ ability to spray fuel into the cylinders, resulting in decreased performance. This issue can be resolved by using a high-quality fuel system cleaner.

Weak Fuel Pump

The fuel pump’s primary function is to deliver fuel from the tank to the engine, requiring sufficient pressure. Insufficient pressure can impede the fuel injectors’ ability to deliver the correct amount of fuel to the combustion chamber, resulting in diesel losing power when accelerating.

While a faulty fuel pump may not pose issues at low speeds, it can hinder quick acceleration. Fortunately, replacing a fuel pump is a straightforward process.

FAQs

1. Are there engine-related issues that can lead to diesel losing power when accelerating?

Yes, engine problems like worn-out piston rings, damaged valves, or a faulty turbocharger can result in power loss. It’s essential to perform a comprehensive engine inspection to identify such issues.

2. How can I prevent power loss in my diesel engine during acceleration?

Regular maintenance, including changing fuel filters, cleaning or replacing air filters, and following manufacturer-recommended service intervals, can help prevent power loss. 

Additionally, using high-quality fuel and avoiding overloading the engine can also contribute to better performance.

3. What role does the turbocharger play in diesel engine power loss during acceleration?

The turbocharger increases air intake pressure, improving engine performance. If the turbocharger is faulty or not functioning correctly, it can lead to power loss during acceleration.

4. How can I identify a malfunctioning turbocharger as the cause of power loss?

Symptoms of a faulty turbocharger may include excessive exhaust smoke, unusual noises (like whining or grinding), and decreased power. A professional mechanic can perform tests and inspections to diagnose turbocharger issues.

5. Can a malfunctioning EGR (Exhaust Gas Recirculation) system affect power in a diesel engine?

Yes, a malfunctioning EGR system can lead to power loss by recirculating excessive exhaust gasses, which can reduce the availability of fresh air for combustion. This can result in reduced engine power.

6. What signs should I look for to determine if the EGR system is causing power loss?

Signs of EGR-related issues may include rough idling, increased exhaust emissions, and a lack of power during acceleration. A diagnostic scan or inspection by a mechanic can confirm EGR system problems.

Check out this video from 8020 Media for more information on causes & solutions for a vehicle losing power when accelerating in general!

7. Can a dirty or malfunctioning mass airflow sensor (MAF) affect diesel engine power during acceleration?

Yes, a dirty or malfunctioning MAF sensor can provide incorrect data to the engine control unit (ECU), leading to improper fuel-air mixture ratios and reduced power.

8. What should I do if I suspect a faulty MAF sensor causing power loss?

Cleaning or replacing the MAF sensor may resolve the issue. Consult your vehicle’s service manual for specific instructions on MAF sensor maintenance.

Conclusion

Now you have knowledge about some reasons why diesel losing power when accelerating. Hope you will find this article helpful and see you again on more Car Maintenance tips with Car From Japan!