The Diesel Selective Catalytic Reduction (SCR) system is an integral component of the engine that reduces nitrogen oxides (NOx) by injecting a urea solution, commonly known as Diesel Exhaust Fluid (DEF), into the exhaust gas stream. This urea solution effectively diminishes harmful nitrogen oxides in the exhaust by converting them into harmless nitrogen and water vapor.
As emission regulations become increasingly stringent, maintaining the diesel SCR system is crucial not only for optimal engine performance and fuel efficiency but also for environmental safety. Proper maintenance ensures the system operates effectively, reduces emissions, and prevents expensive repairs.
Understanding the Diesel SCR System
Before proceeding with cleaning and maintenance, it is essential to understand the basic components of the diesel SCR system.
Key Components:
- DEF Tank: It is necessary to hold the Diesel Exhaust Fluid.
- DEF Injector: The purpose of this component is to supply DEF into the exhaust.
- Catalyst: This is the heart of the SCR system in diesel engines, which is involved in the reduction reactions of nitrogen oxides.
- Sensors: Devices used to measure the concentration of NOx and the pressure and temperature of the system to optimize the diesel SCR system.
Signs of Obstruction of the SCR System
When it comes to diesel SCR units, they are quite delicate, and even minor failures can trigger warning lights or decrease overall performance. Some prominent warning signs include:
- The ‘Check Engine’ lights are a common indicator of malfunctions in the SCR diesel system or, more frequently, in DEF systems.
- If there is urea leakage within the accessible area or if the urea fluid is not administered properly, urea crystals may accumulate around the DEF bottle area.
- A malfunctioning SCR system may register excessive nitrogen oxide measured emissions.
Steps To Be Followed For Maintaining And Cleaning Your Diesel-Based SCR System
If the aforementioned symptoms are noticed, it’s important to understand that it’s time to inspect and clean your SCR system. Regular maintenance and cleaning of these components can help prevent blockages, corrosion, and malfunctions in the system.
Employ Quality DEF
The quality of DEF determines how an SCR system functions. If the liquid is of poor quality or contaminated, the injector will fail to perform its function. To avoid such contamination and crystallization, stick to DEF that complies with ISO 22241. Additionally, store DEF in cool, dry conditions, as prolonged heat can degrade the quality of the liquid.
Occasionally Check on the DEF Tank
Because it’s mostly water, DEF tends to freeze in lower temperatures. It is wise to inspect the DEF tank on and often, especially for leaks and contamination. Depending on how you drive, it may be necessary to refill DEF tanks after some time. However, always check the DEF fluid level and refill when it is low.
Examine and Fix the DEF Injector
The DEF injector becomes noticeable when it is blocked due to urea crystallization or dirt accumulation. When this injector is blocked, the correct amount of DEF may not be dispensed, leading to poor performance of the SCR system. Routine maintenance, cleaning, or replacement may be necessary.
To clean the injector, carefully pull it off slowly and gently. Soak it in a DEF cleaner at the appropriate temperature for a few minutes. Then, remove any remaining deposits with a soft brush. Finally, reattach the injector and check for proper operation.
Monitor Nox Sensors
In tunnels equipped with SCR systems for diesel particulate matter control, the sensors’ ability to recognize nitrogen oxides in the exhaust gas mixture is crucial. If these sensors are defective, malfunction indicators or alarm statuses may be activated even when there is no underlying issue. Periodic sensor checks can be conducted to assess the performance of the SCR system. Carefully wipe the sensors with a cloth, and only replace them if necessary to ensure accurate readings.
Catalyst Cleaning
You must understand the role of the catalyst in the process of catalytic conversion, as well as its potential deficiencies. The catalyst is a crucial component in converting harmful NOx gasses into nitrogen and water.
Can an SCR catalyst be cleaned? Over time, the catalyst may become clogged with soot or carbon deposits, so it should be cleaned or replaced at appropriate intervals. When removing the catalyst, great care should be taken. Use gentle chemical reagents like ICE to clean the SCR. After cleaning, the catalyst should be reinstalled, and its effectiveness should be checked with an emission test. If you are seeking the best options, make a search for ‘SCR catalyst cleaning near me’ and cross-check references and reviews.
Use Regeneration of SCR System
Certain vehicles come equipped with a regeneration feature that helps clean the exhaust system, particularly the SCR on diesel engines. Regeneration refers to the incandescent combustion of carbon and soot deposits accumulated in the system. Depending on the vehicle’s system, this process can be either automatic or manual.
For systems that do not have automatic regeneration, it is recommended to drive at high speeds for an extended period to raise temperatures within the exhaust system, allowing excessive deposits to burn off.
Avoid Short Trips
Most internal combustion engines and their emission control technologies, such as the SCR, are designed for long-distance travel. Short trips do not provide enough time for the SCR to regenerate, leading to the accumulation of soot and pollutants that need to be burned off. Over time, this can result in increased buildup. Whenever possible, opt for longer trips, which allow the SCR to operate optimally and minimize buildup.
Preventive Maintenance Recommendations
Maintaining the diesel SCR system is essential to avoid sudden breakdowns. Adhere to the recommended tools that serve this purpose. Poor diesel quality leads to increased soot deposit generation, causing the SCR, shift forks, and other emission control components to operate less efficiently.
Insufficient DEF can trigger limp mode in your vehicle, limiting engine performance until the tank is replenished. Timely diesel injector repairs are also crucial in this respect.
Routine emissions checks provide valuable insights into problems that need to be addressed. In this case, you can also utilize the SCR system Cummins. Periodically seek the assistance of specialists for your vehicle’s SCR maintenance, especially when vehicle performance is compromised.
Conclusion
Following the steps outlined in this guide will help ensure the longevity and optimal performance of your diesel SCR system, leading to a hassle-free and environmentally friendly driving experience. While regular maintenance can significantly reduce the risk of unexpected breakdowns, there are instances where professional assistance is necessary. If your SCR system triggers warning lights, fails to meet NOx emission standards, or exhibits physical damage, it’s important to seek professional service promptly.
Diesel Components Inc. Has You Covered!
For expert assistance, Diesel Components Inc. is a trusted choice for all your diesel SCR system service needs. We specialize in a wide range of diesel components and provide comprehensive solutions tailored to your specific requirements. Whether you need routine maintenance or repairs, our knowledgeable team is equipped to handle it all. To access our services or inquire further, you can contact Diesel Components Inc. at sales@dieselcomponentsinc.com or call (800) 252-6625 | (952) 890-2885.
