Can vehicle urea be used after being stored for two years?
3 Answers
Vehicle urea that has been stored for two years cannot be used. Additional information: Vehicle urea is a pure but relatively unstable chemical compound. The following four points should be noted during storage: 1. Storage temperature requirements: Vehicle urea requires a storage temperature of approximately -5 to 25°C to avoid exposure to light and high temperatures. In summer, the urea solution should be cooled. If a strong ammonia odor is detected when opening the container lid, usage should be discontinued. Urea will crystallize at low temperatures, expanding in volume by about 7%, so do not fill the urea solution to full capacity—maintain it at around 90% of the container's volume. 2. Vehicle urea has a shelf life: It is recommended to use factory products within six months. For products stored over a year, strong recommendation is to avoid usage. 3. Special storage containers and filling equipment are required: Urea reacts chemically with metals such as copper, iron, and aluminum. Prolonged exposure to these metals can degrade the urea quality, subsequently affecting the SCR system's performance. Special filling equipment must be used when refilling the vehicle with urea.
As someone who frequently deals with diesel vehicle maintenance, I advise against using diesel exhaust fluid (DEF) that has been stored for two years. DEF typically has a shelf life of around 18 months, and storage conditions are crucial—keep it away from light, in a cool place, and tightly sealed. Over time, DEF can crystallize, degrade, or lose concentration. If used, it may clog the injector or damage the SCR system, leading to repair costs of at least a couple thousand dollars and negatively impacting emission compliance. I recommend carefully inspecting the bottle for any sediment. If the liquid appears cloudy or separates when shaken, discard it immediately and replace it with fresh DEF. Always check the production date when purchasing DEF and ensure leftover fluid is tightly sealed after use. Don’t cut corners—safety comes first.
I have quite a bit of car maintenance experience and have made the mistake of storing urea for too long myself. Two years ago, I bought a bottle and forgot about the remaining half in the garage. During summer, the heat caused condensation on the outside of the bottle. When I shook it, I noticed crystallization at the bottom. A friend at the repair shop told me it had gone bad and was unusable. High temperatures accelerate degradation, and once the ammonia evaporates, its effectiveness drops, potentially triggering system errors. Now, I opt for smaller bottles and only buy more when I've used them up to avoid waste. When storing, ensure the area is well-ventilated and dry, and keep it out of direct sunlight. If the bottle is unopened and stored in stable conditions, you might check the density to confirm its quality, but two years is too long—it's safer to just replace it.
