3 Ways to Reduce Black Smoke in Diesel Engines

Diesel-powered vehicles typically get a bad reputation because they are sometimes seen spewing black smoke from their exhaust.

To a casual observer, it looks like these vehicles are polluting the environmental more than any other vehicle which uses gasoline. After all, we usually don’t see black smoke coming out of the exhaust of regular vehicles which use gasoline-powered engines.

However, both types of engines are just as bad for the environment. The only difference is that the gasoline engines produce emissions which are either white or invisible. That is why they don’t get criticized as much as diesel engines.

Bad appearances are often a motivator for wanting change.

See Also: Causes of Blue Smoke From an Exhaust (and How to Fix)

How to Reduce Black Smoke From a Diesel Truck or Car

If you have black smoke coming out of your tailpipe, there are steps you can take to reduce the amount of smoke. Even if you don’t care about the cosmetics of the black smoke, it is important to reduce it at least for financial reasons.

If black smoke continues to come out of your vehicle, then you will in all likelihood experience fewer miles per gallon. This means that you will be going to the gas station more often and spending more of your hard-earned money on gas.

Fuel prices are high enough as it is so if you care at all about the fuel economy of your vehicle, you will want take the necessary steps to stop this from happening.

Below are the top 3 ways to reduce black smoke in a vehicle which has a diesel engine.

1) Common-Rail Fuel Injection System

common rail diesel Duramax

There are new diesel-powered vehicles which come with a common rail fuel injection system. This is a high-pressure injection system that feeds fuel directly to the solenoid valves.

In older diesel vehicles, the pump nozzles used a low-pressure system to pump the fuel. This is what normally causes black smoke to come out. But in modern common rail systems like in Duramax engines, there will hardly be any black smoke or emissions coming out at all.

When you go to purchase a diesel truck, try to find one which has the common-rail fuel injection system in it. Then you will automatically have a vehicle that produces less black smoke.

2) Replace (or Clean) Your Air Filter

clogged air filter

The internal combustion process of any diesel vehicle requires the proper amount of air intake in order for the fuel to be completely burnt. If there is an inadequate amount of air coming into the engine, then the fuel will only burn partially. The result of this will be black smoke being emitted from the exhaust system.

Fuel needs to be fully burnt because it will produce water and carbon dioxide. These two elements will not cause black smoke. That is why the right combination of air and fuel is so critical if you want to avoid producing black smoke.

It’s easier than you think to check your air filter to see if it is clogged or dirty. This might be what is preventing air from flowing inside. If that is the case, then you’ll need to replace your air filter, or if you have a reusable filter like K&N, clean it according to the included instructions.

3) Fuel Additives

best fuel injector cleaner

As you continue to drive your vehicle, combustion deposits and debris will gradually build in the cylinder chambers and fuel injectors. These deposits will mix with the fuel and do two things.

First, they will degrade the performance of the engine and reduce its fuel economy. The second thing is they will cause that black smoke to come from the exhaust system.

Fortunately, there are detergent additives which you can mix in with your diesel fuel in order to clean out these harmful deposits. Once you do that, you should see the black smoke disappearing after a couple of days.


2 thoughts on “3 Ways to Reduce Black Smoke in Diesel Engines”

  1. kubota d1105 motor blowing excess black smoke injector pump rebuilt new governor installed new washers and excess fuel excess pipe fitted even when governor has closded of fuel it blows black smoke and have to turn key off to shut motor down


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