How Much DEF System Replacement Cost?

DEF systems are required for modern diesel engines to be able to run. This is because diesel engines put out significantly more pollutants than gasoline engines. So, environmental regulations mandate that all modern diesel engines be equipped with a DEF system.

 The total DEF system replacement cost will vary from vehicle to vehicle. In a best-case scenario, your DEF system itself is fine and you just need the heater replaced. Replacing a DEF heater will cost about $800 for parts and labor. Getting a DEF filter cleaned generally costs around $1500 dollars in labor. If the filter is damaged and needs to be replaced, the parts can cost as much as $2000 to $5000 dollars..

A complete DEF is expensive and complex. Luckily, when it comes time to perform maintenance on a DEF system, most of the time it just needs to be cleaned. The bad news is that cleaning a DEF filter requires a professional mechanic and specialized tools.

In this article, we will detail the total DEF system replacement cost. We will also cover some things you can do to make your DEF system last longer.

If you just need your DEF heater replaced, it can cost under $1000. If regen is not working and you have to have your DEF filter professionally cleaned costs about $1500 dollars. If your filter is not able to be cleaned and needs to be replaced, it can cost as much as $2000 to $5000 in parts alone..

What Is DEF Fluid?

The active component in DEF (Diesel Exhaust Fluid) is synthetic urea. When you buy DEF, only 32.5 percent of that is urea. The remaining 67.5 percent is deionized water. As you may expect, DEF weighs 9.08 lbs per gallon, which is a bit heavier than water’s 8.34 lbs per gallon.

While some DEF is marketed as AdBlue and Blue DEF, DEF is actually a clear liquid that smells like ammonia. DEF freezes at 12 degrees Fahrenheit, but most trucks have some sort of DEF heating system to keep everything running properly in extremely cold weather.

How Does A DEF System Work?

Diesel particulate filters work by trapping soot particles from the engine exhaust. This prevents harmful pollutants from reaching the atmosphere. A catalytic converter does something similar, but works in a different way.

The most widely used diesel particulate filters are cellular ceramic honeycomb filters. In this type of filter, ends are plugged in a checkerboard pattern. This forces soot to flow through the filter walls. The engine exhaust gasses are able to flow through the walls but the soot can’t, so it becomes trapped.

While a catalytic converter reduces gas-phase emissions by flowing exhaust gasses through the catalyst, DPF systems work by trapping the solid particles. Later, the system oxidizes and cleanly burns off the material during regeneration.

Why Would You Need To Replace Your DEF System?

Because diesel engines without DEF systems produce too many pollutants, a diesel engine will completely shut down if it runs out of DEF fluid. This can be frustrating, because when you run out of DEF, the symptoms are similar to running out of fuel, even though you have plenty of diesel left in the tank.

If you run your DEF system dry too often, it will break down a lot faster than if you kept it filled up. There is a similar phenomenon that happens with fuel pumps if you constantly let your vehicle run out of gas.

In addition to that, DEF systems are complicated electromechanical devices. As you would expect, they break down from time to time.

One of the most common reasons that a DEF system fails sooner than it should is overdosing. Overdosing happens if you have a DEF injector nozzle that is partially open. This can also happen if your DEF lines are clogged if your DEF pump is not working.

How Long Does DEF Last?

If DEF is stored between 12 and 86 degrees fahrenheit, it will last for up to 12 months. For the longest possible shelf life, make sure to store your DEF in a cool, dry place. DEF is particularly easy to contaminate, so If you store your DEF improperly, impurities can easily gather in it.

How Much Does DEF Cost?

DEF can run anywhere from $6 to $10 per gallon. Overall, the requirement for DEF increases the operational cost of any diesel vehicle by 10 to 20 cents per gallon of fuel.

How Much Does It Cost To Replace A DEF System?

To have a DEF system professionally overhauled, expect to spend about $1,500. If it has more than 200,000 miles on it, it’s recommended to replace the DEF system altogether. Completely replacing a DEF system can cost 10,000 or more.

What causes DEF system failure?

DEF is just pure urea diluted with distilled water. So, as the water evaporates, it allows solid urea to precipitate out of solution. Most of the time when a DEF head is damaged, it’s because there were too many solid particles in the system.

This is why it’s so important to store your unused DEF in a cool, dry place and in totally sealed containers. This will prevent anything from getting in your DEF, and it will help keep it chemically stable in the process.

How Much Does A DEF Filter Cost?

Depending on the vehicle, a DEF particulate filter can cost between $2,000 to $8,000. Most of the time the filter does not have to be completely replaced.

Remember, when performing a regen, you are really just performing a low-level built-in cleaning of the filter. If that does not cut it, you will have to have the filter professionally cleaned. In particularly bad cases, the DEF filter needs to be replaced.

What Will Happen If My Truck Runs Out Of Diesel Exhaust Fluid (DEF)?

The EPA requires vehicles to make it so that vehicles cannot run normally without DEF (Diesel Exhaust Fluid). Long before the vehicle runs out of DEF, the driver is given a series of alerts. In most passenger vehicles, when the DEF tank level drops below 10% a yellow warning light comes on. Then, at 5% the yellow light begins to flash.

If the vehicle is allowed to run out of DEF, the engine’s power is dramatically reduced and a solid red warning will be displayed. The fastest you will be able to go is 5 mph until the DEF tank is refilled.

How To Make Your DEF System Last Longer

1. Regenerate Often

When you perform a DPF regeneration, you are cleaning all the soot of the filter that was captured over a period of time. Most of the time, regeneration will happen automatically, but this is not always the case.

By the time the DEF light comes on, the filter is already way too dirty. So, for best performance, DEF regeneration should be performed about every 200 miles.

2. Use The Correct DEF Fluid

Servicing your vehicle is important to keep it in good shape, and your DEF system is no exception. Using quality DEF fluid and making sure that you don’t run out frequently will ensure the longest-possible service life for your DEF system.

DEF systems do not like mineral or semi-synthetic blended oils. So, nearly all DEF systems require low or very low SAPS-additive oils. If you are not sure what kind of fluid is best for your vehicle, look into its ACEA C1-C5 ratings.

I cannot stress enough how important it is that you use the correct grade oil that meets your car manufacturer’s specification. If you don’t follow your manufacturer’s recommendation, you could run into serious issues.

3. Fuel Quality

Fuel quality is important. While it’s true that diesel engines are robust, if you regularly use low-quality fuel, your engine will suffer and place higher strain on your vehicle’s DEF system.

Sure, the engine will work, but damage is happening over a long period of time.

If you always put low grade diesel in your tank, that will show when it comes time to do any kind of service on your engine. Anything that comes into contact with fuel will have a thick, dark layer of soot covering it.

The DEF system is no exception. It will all get completely filled and clogged with soot. This makes it so the DEF system’s built-in regen is not enough to clean the filter. The only other option at that point is paying a professional well over $1500 to clean it.

If the damage is too bad and the filter has to be replaced, that can cost anywhere from $5000 to $1000 depending on the vehicle.

How To Switch To A Different Brand Of DEF

Even though they are all designed to do the same thing, not all DEF is the same. So, if you are switching to a new brand of DEF, the best thing you can do is run the tank as empty as possible before refilling.

This will ensure that as much as possible of the old DEF is purged from the system.

Can You Run A Diesel Without DEF?

Technically, yes. DEF is not required for a diesel engine to work. The problem is that all modern diesel vehicle computers will not allow the engine to run if there is no DEF. Because of that, make sure to check your fluid levels frequently to make sure everything is kosher.

DEF is clear, so if your DEF looks murky or cloudy, then chances are something is wrong with your DEF system.

How Many Miles Will 1 Gallon Of DEF last?

Generally speaking, 1 gallon of DEF will last somewhere between 300 and 500 miles. Most trucks end up needing 1 gallon of DEF for every 50 gallons of diesel fuel.

How Much DEF Does 2021 Duramax Use?

The new Duramax engines are very efficient in terms of their DEF use. The 5 gallon DEF tank on vehicles that use the Duramax LML engine can last for up to 5,000 miles of driving before you need to refill it.

Conclusion

Even though they are not required for the engine to actually operate, DEF systems are required for modern diesel engines to run. The fact of the matter is that engine’s output far more pollutants than gasoline engines. So, there are regulations in place that help mitigate that.

Unfortunately, when a DEF system goes out, it leaves you stranded. It’s hard to get to work to pay for a new DEF system when you can’t get to work.

We hope this article helped you learn more about the total DEF system replacement cost. Thanks for reading!