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My Car Is Losing Power: Why Your Diesel Engine is Slowing Down

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My Car Is Losing Power: Why Your Diesel Engine is Slowing Down

If you’re looking for a powerful engine, consider diesel vehicles. Notorious for being notably more powerful than their gasoline counterparts, diesel engines produce a level of power that many vehicles- commercial, fleets and bulkier autos- benefit from.

That’s not to say that diesel engines have more horsepower or can accelerate quicker.

Torque Is The Power In Your Diesel Engine

In reality, gasoline engines actually have that beat- but what diesel engines far surpass regular autos in is torque.

What is torque?

The best way to describe torque would be a twisting force, that causes an object to rotate.

For your diesel vehicle, torque is directly related to your engines rotational force and speaks to the measurement of just how much that force is available when the engine is asked to exert itself. Torque is directly created by the pistons within an engine; as they create movement on the engines crankshaft, it causes it to twist. This movement is sent to the vehicles wheels through the drivetrain and transmission.

The amount of torque your vehicle produces varies; it depends on the size of the engine and the design of the engine.
But, diesel vehicles produce a lot more. The more torque an engine has, the easier it is for the vehicle to do some seriously hard work- towing, hauling, climbing up steep hills etc.

PSA: This is why commercial vehicles and fleets tend to always be diesel.

Can I lose torque?

Declining torque is only a symptom of an engine slowing down. You cant “lose” torque, but your diesel engine sure can lose the ability to create it.
Gradual loss of power in an engine is inevitable, but a sudden drop in power indicates something is going on inside.

Wondering why your engine seems a bit- blah?

You Engine Could Be Losing Power Because of These Five Reasons

It sucks when you feel the power draining from your engine- but the good news? They’re all fixable.

And while we really don’t recommend trying to mess with your diesel engine yourself, having a look into things may make the repair process a little more simple.

Contaminated Fuel Decreases the Power in Your Engine

General rule of thumb: you should be changing your fuel filters at least once a year for a number of reasons.

Clogged fuel filters inhibit the flow of diesel through the vehicle. With diesel or petrol not running through your vehicle correctly, you end up with little hesitations or interruptions in the engine cause abnormal combustions.

Remember, your fuel filters are quite literally the block between contaminations of most fuel and your engine. With faulty or clogged fuel filters, the diesel being sent through your vehicle likely contains a bunch of contaminants that will peeve off your engine.

Bad Air Filters Can Lead to Engine Power Loss

Along the lines of filters, air filters are also a common cause of decreased power in an engine.

Just how fuel filters capture any contaminants in the fuel, air filters stop dirty air from reaching your engines chamber.

This chamber – the internal combustion chamber- is where diesel and air are mixed together to generate the power needed to actually run your vehicle. Dirty air doesn’t mix well with diesel fuel and won’t produce as much clean, powerful- well, power. Dirty air filters also limit the amount of air that reaches the combustion chamber in general, so in most cases there may not be enough to even produce power within the engine.

Air filters should be changed once a year, similar to fuel filters.

Low Compression = Low Power

The combustion process relies on good cylinder compression throughout.

Cylinder compression confines and mixes air and fuel into a very small volume within the engines cylinder. This process, and it’s ignition, is what produces the power within an engine to operate the vehicle. More specifically, since there are now spark plugs in a diesel engine, the process of compression within a diesel vehicle is quite literally what produces the power needed to operate the vehicle.

Because of this, diesel engines need a compression of 350+PSI; if you’re compression is running low, so will your engines power. Diagnosing a low cylinder compression is important in early stages, and an experienced diesel repair shop can take it from there.

PSA: This is really something you shouldn’t deal with at home.

A Lack of Power Could Mean a Faulty Oxygen Sensor

Oxygen sensors measure the amount of gas leaving your vehicles engine, to determine the air to fuel ratio that exists in a vehicles engine.
The sensor- positioned inside of the exhaust stream- ensures that the fuel injection system and engine timing can do their jobs sufficiently.

A faulty sensor wouldn’t be able to send the correct ratio information to the electronic control module, and it would likely indicate that there are issues within the engine and it’s outputs.

Without the correct feedback, your engine could be performing poorly.
(Imagine being given the wrong data and instructions to go off of- you’d likely get clogged down trying to figure out what to do and the result wouldn’t be great.)

Clogged Exhaust Pipes

An exhaust system is made up of two parts- two very important parts.

The muffler has a simple, but important job- limit the amount of noise that a vehicle makes.

The catalytic converter cuts down the amount of pollution stemming from exhaust gasses.

If the exhaust pipe, or any of it’s filters aren’t working up to their usual standard, the functionality of the engine goes down the drain. You’ll likely experience engine power loss- but the big tell tale sign of a clogged exhaust pipe is really slow acceleration.