How to Deal with Urea Solution Crystallization?
3 Answers
Before parking, the vehicle should idle for a short period to allow the reactants to be discharged first. This is because shutting down the engine abruptly may lead to urea accumulation in the exhaust pipe. After turning off the engine, do not immediately disconnect the vehicle's power supply. The purpose is to clear the urea in the pipelines to avoid crystallization and blockage. The entire purging process lasts approximately 30-120 seconds. The following are the methods for using urea solution: 1. Use certified solutions: Always refill diesel and urea solutions produced by reputable manufacturers. Excessive impurities or other component issues may damage the catalytic converter. 2. Regular replacement: Replace the urea filter regularly. For air-driven urea pumps and air-assisted urea pumps, the air filter should also be replaced periodically. 3. Regular cleaning: The interior of the urea tank is prone to accumulating impurities, sediments, and crystallization, so it should be cleaned regularly. Additionally, the exterior of the urea tank should also be kept clean, especially around the tank lid. When refilling urea, ensure no dirt falls into the tank.
Urea crystallization is a common issue in diesel vehicles, especially in cold weather when urea tends to solidify and clog the system. Based on my experience with long-distance driving, if you encounter crystallization, avoid forcibly starting the engine to prevent further damage. It's best to rinse the nozzle and pipes with warm water (not too hot, around 40°C) to soften the crystals or use commercially available specialized cleaning agents to dissolve and flush them. For prevention, choose reputable urea solutions like AdBlue and avoid mixing in impurities or oil. After parking, regularly check the system's sealing to prevent leaks. Be patient during the process—don’t rush. If you can’t handle it yourself, visit a professional repair shop early; they have the right tools for a thorough cleaning. Additionally, avoid prolonged parking in low temperatures to reduce the likelihood of occurrence. Timely maintenance protects the emission system, extends component lifespan, and saves costs.
The urea crystallization warning light came on in my car last time, and I handled it myself. Crystallization usually forms as white powder blockages at the nozzle or tank interface. First, disassemble the nozzle components, carefully scrape off the hard deposits, or use a cleaning agent to dissolve the residue, wipe it clean, and then reassemble for testing. At the same time, check the urea line for any damage or leaks and repair them. Preventive measures are important: use high-quality urea, perform regular maintenance, and in winter, it is recommended to add a special anti-crystallization agent to reduce the frequency of occurrence. The entire process requires careful attention to save on repair costs, but if crystallization severely affects driving, it is advisable to seek professional help to ensure safety and reliability. After handling, test drive more to monitor and prevent recurrence.
