When it comes to owning a diesel truck, there are some items to keep in mind when you go about your daily driving and routine maintenance. After all, as we discussed in our previous blog, there are certain key factors that differentiate diesel trucks from your standard gas trucks — one of them being how you perform routine maintenance on your diesel truck.

It’s likely one of the reasons you set out to buy a diesel truck in the first place was because they require less maintenance and repairs. While this is usually the case, that doesn’t mean you’re off the hook either, though.

Here at Texas Diesel Company, our diesel mechanics have compiled a list of a few actions to follow that will ensure your diesel spends less time with the mechanic and more time out on the road. If your diesel truck is in need of maintenance or repairs from a professional diesel mechanic, schedule an appointment at our diesel shop in the Dallas-Fort Worth area today.

The following are ten of the most important diesel maintenance tips to follow in order to maximize the efficiency and life expectancy of your diesel truck:

#1: Always Keep The Air Filter Clean

While this is certainly important with any motor vehicle, it’s even more imperative with a diesel engine, so you’ll need to keep a closer eye on your diesel’s air filter than you have with previous vehicles. Diesel engines use a lot more air intake than gas engines do, so they must be kept clean to allow enough clean air to circulate throughout the components. Many modern diesels will include factory-installed electric sensors that will notify you when it’s time to inspect or replace your air filter. If your diesel truck is an older model, though, you will simply need to routinely keep tabs on your air filter’s condition, ensuring no debris it hasn’t collected any dirt or debris.

#2: Change Your Diesel Fuel Filter Frequently

It is much easier for diesel fuel to become contaminated compared to traditional gasoline, making the fuel filter of your diesel truck a very important item. One of the best ways to ensure your diesel truck continues to operate at peak performance and efficiency is to replace your fuel filter often, sometimes even ahead of the recommended schedule provided by your diesel mechanic. If you neglect to replace your diesel filter on a regular basis, it can lead to serious engine damage over time.

#3: Check Your Oil Levels In Between Oil Changes And Tune-ups

Your diesel truck will burn through oil under normal operation faster than a traditional truck, so monitor it closely to ensure that your oil level is maintained at an adequate level in between your trips to the diesel shop.

To properly check your diesel oil:

  • Let your engine cool for at least 30 minutes.
  • Make sure your truck is level.
  • Pop the hood and check the dipstick.
  • If the oil needs to be replenished, check the owner’s manual for directions.

#4: Purge Water From Your Diesel Fuel System

Fun fact for you: diesel fuel can contain water. While most modern diesel engines will come equipped with a water/fuel separator, it’s a good idea to check your owner’s manual to be certain your diesel truck does.

If it turns out your diesel truck does not, you will need to remove the water manually. Your owner’s manual will outline how to properly perform this or you can simply take it to your local diesel mechanic shop to let them take care of it — if you’re in Texas, this should be TxDC!

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#5: Black Smoke Isn’t Always A Good Thing

While many diesel drivers love rolling some coal, excessive amounts of black smoke always means bad news, particularly issues with your injector:

  • Worn-out injectors
  • Dirty injectors
  • Faulty injection timing

To prevent this from happening with your diesel truck, you can install glow plugs that will assist in burning the fuel. If you experience unwarranted amounts of black smoke while driving, stop immediately, use a diagnostic tool to determine which injector is the culprit, and fix the issue before it gets a chance to worsen things.

#6 Avoid Long Trips During your Diesel’s Break-In Period

If you just bought a new diesel truck, your engine will need to be broken in. It takes longer to break in a diesel’s engine compared to others — more specifically, between 500 to 1000 miles. Most manufacturers will recommend to drive them only in stop-and-go traffic and city streets during this time period. So if you’re planning on taking a vacation right after purchasing your new diesel, opt to take another vehicle instead no matter how inclined you may feel to drive it. By properly breaking in your diesel engine, your truck will be able to improve its power and efficiency over time.

#7: Closely Monitor Your Cooling System

If it wasn’t made clear by now, your diesel engine is not like a gas engine. The same applies to how your diesel engine cools — you can’t simply shut it off and let it cool for a few minutes when it overheats. In many cases, an overheated diesel engine is damaged beyond repair, which is why it’s so important to actively prevent your diesel engine from ever overheating.

The best way to do this is by properly maintaining your cooling system. Monitor your coolant levels often, ensure the coolant filter is clean or replaced when needed. In addition, it’s always a good idea to allow your engine to rest in idle for a minute or two prior to shutting it off when you have the capability — especially if you’ve been working it hard.

#8: Warm Your Diesel Engine In Cold Weather

diesel maintenance Texas winter

Diesel engines and cold temperatures are far from compatible. When temperatures hit zero degrees Fahrenheit or lower, diesel engines become incredibly difficult to start. This is why they come equipped with a block heater. As long as you make sure to plug your block heater in when cold weather is coming to keep your engine warm through the freezing temperatures, you shouldn’t have any difficulties starting it up. If you’re not sure where your block heater is located, check your diesel manual.

#9: Do Your Best To Keep Your Tank Full

To prevent the build-up of moisture and water in your fuel tank, keep it full as frequently as possible, especially if you don’t drive it very often. While it’s not necessary to refill your tank every time you drive it or every time it gets below halfway, always avoid driving while close to empty. This will help keep your tank in a healthy state.

#10: Don’t Keep Your Engine In Idle For Long Periods

Prolonged idling of diesel engines is not only bad for the environment, but it also can significantly reduce your engine’s lifespan. This is because it leads to insufficient lubrication on the piston wall, leading to piston and cylinder block scoring — something you don’t want.

Back in the “old” days, many diesel mechanics would tell you to run your engine constantly to prevent your fuel from gelling. With modern diesel fuel and motors, this is NOT a concern. If you keep your truck idling constantly, you’re really just wasting fuel and reducing the lifespan of your vehicle.


We hope that you will take our tips for proper diesel maintenance to heart and practice them on a regular basis. If you do, your diesel truck should keep performing great for many years to come, whether it’s a new model straight from the dealership or a used diesel truck.

If you want to get the best performance out of your diesel truck, you need a team of diesel mechanics you can trust. Reach out Texas Diesel Company to schedule an appointment with us for diesel repairs, engine upgrades, routine diesel service, or anything in between.