Many recent diesel cars would be affected by a risk of breakdown with their AdBlue device. Here are some tips to avoid paying a (heavy) bill.
If you bought a recent diesel car, there is a good chance that it is equipped with a AdBlue tank. Remember that this liquid, composed in particular of urea, has become essential for the operation of many diesel engines.
Its goal ? Decrease very strongly nitrogen oxide emissions (NOx), and thus meet new environmental standards.
Regularly, the owners of these cars must therefore refuel AdBlue (recognizable by its blue cap), autonomy varying from approximately 5,000 to 20,000 km depending on the vehicle. And beware of running out of fuel, because in this case the car fails and prevents the engine from being restarted!
However, the Adblue additive can cause breakdowns, reports Que Choisir, a French consumer defense website. “Potentially, most cars less than 10 years old are affected, resulting in a fairly heavy bill to be borne by the consumer“ warns the site.
“1,470 EUROS TO PAY”
Testimonials are multiplying from drivers who see an alert message displayed “anti-pollution fault“or the AdBlue logo followed by “impossible to start in XXX km“.
Que Choisir sets an example of vehicle owners Citroën or Peugeot who lament that “The AdBlue tank sensor is faulty and no longer detects the presence of the product. However, without this detection, after 2,000 km, the car will no longer start. €1,470 to pay to change the room.“
This sensor is crucial, because it is completely inseparable from the AdBlue tank and then you have to replace the whole. Que Choisir cites Peugeot, for example, which recognizes that “sOn some vehicles equipped with the first version of the Selective Catalytic Reduction (SCR) system on Euro 6 diesel engines, malfunctions may occur“. The builder adds that “the SCR is a sophisticated system which can sometimes lead to the detection of false alarms. Illumination of the SCR warning light therefore does not necessarily lead to the replacement of the AdBlue tank.
Always according to What to Choose, Audi, Kia, Mercedes, Renault, Seat, Skoda or Volkswagenwhich equip some of their models with the same SCR particulate filter technology, may also be affected by the phenomenon.
THE FAULT OF “CRYSTALLIZATION”
Que Choisir explains that circuit design of AdBlue by the manufacturer is not the only factor involved. The problems would come mainly from other phenomena:the degradation of the liquid from 25°C and, above all, its crystallization.“The latter occurs in particular when the temperature of the exhaust gases is not high enough (less than 260°C) for the AdBlue to play its role as an anti-pollutant and when the AdBlue is exposed to a lower temperature or equal to -11°C.
The phenomenon can then lead toobstruction of the SCR catalyst, deformation of the tank, the level sensor can also be blocked, the liquid pump can become clogged, as can the filler valve”, etc. In short, so many reasons that lead immediate stop of the vehicle… and important bills as a result!
WHAT TO DO?
The main advice that is given is this: not completely filling the tank in order to preserve the vent and the filler plug so that they are not blocked or obstructed during crystallization. For example, put 13 liters maximum when the tank can hold 15.
The other solution is to use a anti-crystallizing product to add to the AdBlue tank. But, there again, it is an additional cost for the motorist.
About the financial support for the repairs of this defect, it seems that it is not guaranteed. For example, at Peugeot, it would be granted above all “only to cars less than 5 years old and with less than 150,000 km on the clock.” For other manufacturers, “reluctant to put their hand in their pocket, even practical: taking charge of the repair, or at least a contribution to the repair costs, is really sporadic“.