Will a clogged urea nozzle affect the urea pump?
3 Answers
Urea nozzle clogging will affect the urea pump. When the nozzle is clogged, the urea pump will experience poor atomization, leading to crystallization. Performance failure of actuator components causing clogging: When the exhaust temperature sensor has a performance failure, for example, if the actual exhaust temperature is 100 degrees Celsius but the sensor reports 200 degrees Celsius to the computer, the system will prematurely inject urea. The urea injected into the low-temperature exhaust cannot hydrolyze and vaporize, naturally forming crystals on the catalyst carrier. Over time, these form hard urea crystal compounds. Vicious cycle caused by disabling the urea system: This leaves the nozzle isolated and helpless, forced to endure high temperatures without relief. Urea pumps and pipelines that remain inactive for long periods will have residual liquid inside evaporate, leading to crystallization and blockage.
As a long-haul truck driver, I've experienced urea nozzle clogging several times. Once on the highway, the urea system warning light came on. When I stopped to check, I found the nozzle completely blocked, which eventually caused the urea pump to fail. It turns out that when urea injection is obstructed, the pump has to work extra hard to maintain pressure, leading to overheating and even burning out the coil over time. During repairs, the mechanic told me the motor inside the pump was also damaged, and replacing the whole unit cost me several hundred dollars. Now I regularly flush the nozzle with special cleaner to ensure smooth flow, which has saved me a lot of trouble and money. Remember, while clogging may seem minor, prolonged neglect can damage both the pump and the entire emission system, severely affecting vehicle performance. If this happens, don't push your luck - get it fixed professionally right away. Safety comes first.
I've been working in auto repair shops for over a decade. Urea nozzle clogging can indeed affect the urea pump, such as when the pump keeps pressurizing after complete blockage, causing the sensor to detect abnormalities and automatically shut down or burn out internal components. Last year, I repaired a vehicle where complete nozzle blockage led to excessive pump pressure and fluid leakage, resulting in the entire SCR system being scrapped, costing the owner over a thousand to replace the pump. During repairs, we first clear the nozzle and then test the pump voltage to avoid chain reactions. I recommend everyone regularly check nozzle flow with a diagnostic tool, especially paying attention to impurities and deposits when changing urea fluid. Early detection and repair can significantly extend the pump's lifespan—don't wait until the dashboard alarm goes off to panic.
