AdBlue tips

Posted on March 19th, 2019 by Rob Marshall

AdBlue tips

Whether you own a modern Euro 6 diesel, or you lease/hire one, you will notice that you have to add another fluid to the car, other than petrol and (possibly) oil. AdBlue is a harmless solution, made mainly of pure water and urea. It is injected into the exhaust system to reduce the harmful NOx element of the diesel combustion process. Yet, many cars will stop running, if the AdBlue tank runs dry. Typically, a car will use around 1.5 litres of AdBlue every 600 miles.

Yet, the motor trade has alerted us of consumer issues with the system, which we hope to alleviate with these top tips:

1. Do not pour AdBlue into the diesel tank. The car does not dose AdBlue into the fuel system but into the exhaust, to treat the post-combustion gases. Familiarise yourself with the location of the AdBlue tank and the location of the filler. Pictured is the AdBlue top-up location within the boot of a Peugeot 308.

2. AdBlue deteriorates over time. Never use AdBlue after its expiry date has passed and, unless you cover very high mileages, do not stockpile large quantities at home.

3. Ultra-violet light speeds-up AdBlue’s deterioration and this can damage your exhaust system’s delicate catalyst. Therefore, buying bottles that have been sitting outside a petrol forecourt may not be a good idea. Instead, look for bottles that have been stored indoors, or in the dark.

4. Do not ignore AdBlue refill messages. The engine may stop running and may not start again, even after you have refilled the tank, until a garage has ‘reset’ the system using its diagnostic equipment.

5. Do not overfill the AdBlue reservoir. This can create a vacuum inside the tank that prevents the AdBlue from being injected into the exhaust initially and this could cause an engine management light to illuminate. On some cars, the AdBlue pump and circuitry are located on top of the tank, so overfilling risks moisture contamination that can damage the circuits.