adblue tank

Why is it forbidden to empty AdBlue on diesel?

Most diesel cars are equipped with the Selective Catalytic Reduction (SCR) system; which catalyzes the conversion of NOx (nitrogen oxides) to nitrogen and water using urea solution (AdBlue) as the reducing agent.

What is AdBlue? What does it do?

AdBlue is a nitrogenous (urea) and water-based solution, a liquid that is sprayed into the exhaust gases from the engine; in order to reduce the rate of NOx gases in the exhaust. AdBlue fluid, a component of the SCR (Selective Catalytic Reduction) system, consists of 32.5% urea and 67.5% deionized water. This liquid, which is sprayed on scorching exhaust gases coming out of the engine; turns into ammonia. As a result, it breaks down harmful NOx gases to a great extent and enables them to be released into the atmosphere as harmless nitrogen gas and water vapor.

The urea solution indicator appears on the car instrument panel display and shows the approximate amount in the urea solution container. A “Low Urea” warning message usually appears when the level starts and drops. If no refueling occurs and the urea in the tank approaches the very low level, the “Refill Urea tank” warning message is displayed. In this case, the tank must be refilled soon. Also, some models list the kilometers that the car can travel until the next filling.

adblue level
AdBlue level

If AdBlue runs out

If the driver ignores all the warning messages and does not fill the corresponding tank with urea; the car cannot be restarted after the engine is closed with the ignition key. In another words, the car can stay on the road at any time. Imagine doing this in a remote area, with no AdBlue gas station nearby. Once the stimulus system reaches the final state and the car restart is deactivated, the restart option will only be restored if the urea tank is full.

Don’t put in your diesel tank

The tank for the urea solution supplement is located next to that of the oil tank. Be very careful not to add urea solution to the fuel tank; as this will adversely affect engine performance, causing various malfunctions. Also, never use the urea solution mixture with additives or water and only fill the ISO 22241 prescribed urea solution.