AdBlue™ in diesel tank

Quick and easy guide to the problem and the solution of accidentally putting AdBlue in the diesel tank.

AdBlue™ in diesel tank: The problem and solution

In order to meet Emission Standards, diesel vehicles need to reduce their emissions down to a certain level depending upon the engine size. In response to this, exhaust technology has been introduced that uses a fluid known as AdBlue™ (DEF) to reduce the Nitrous Oxides present in emissions.

AdBlue™ is commonly mistaken as a fuel additive, when in fact it should not be mixed with diesel at all. Whereas diesel is for the running of the engine, AdBlue™ is designed for the SCR system in the vehicle exhaust and therefore is dispensed into a completely different tank to the diesel.

Whilst AdBlue™ has been used in some vehicles since 2005, updates to the Emission Standards have seen more and more needing to comply. To date it covers all new trucks, buses, agricultural and plant equipment as well as some passenger cars. For many, AdBlue™ is still relatively new and filling up the vehicle with both fluids is not yet second nature. Even for those that are used to it mistakes still happen...just look at how often people put petrol in their diesel car! So what happens if you do the dreaded and accidentally put AdBlue™ in your diesel tank?

What happens if I accidentally put AdBlue™ in my fuel tank?

To help avoid confusion, a lot of vehicles have a blue fill cap for the AdBlue™ tank and black, red or green for diesel, and on many HGVs the AdBlue™ and diesel fill points are positioned quite far away from each other. However this isn’t fool proof and a driver mistakenly putting AdBlue™ into the diesel tank can have disastrous consequences.

Ad Blue Diesel Points
Image adapted from © Photo by Kickaffe (CC BY-SA 4.0)

Generally speaking, accidentally putting diesel into your AdBlue™ tank is unlikely as the AdBlue™ fill point is designed for a smaller spout nozzle (19mm), making it impossible for larger diameter diesel spouts to fit. The other way round however has become a common problem.

If the unfortunate situation arises that a driver has added AdBlue™ in the diesel tank, this can cause costly damage. AdBlue™ is not compatible with many materials so it can corrode the pipework and components in the fuel system. This can cost thousands of pound worth of damage, not to mention the loss of use of the vehicle until a professional gas drained the tank, flushed out the system and carried out all repairs.

What do I do if I have put AdBlue™ into my diesel tank?

If you have unfortunately done this, then it is important to follow the below steps...

  • DO NOT turn on your vehicle engine - this will circulate the AdBlue™ round the vehicle
  • Get a professional to drain the tank and dispose of the contaminated fluid safely
  • Get a trained mechanic to check the damage caused and replace the filters that will have absorbed the AdBlue™
  • Contact the vehicle manufacturer or dealer for official replacement parts that have been damaged or corroded

So what can you do to prevent drivers from putting AdBlue™ in the fuel tank?

How do I make sure I don’t put AdBlue™ in my diesel tank?

If you're reading this, it probably means this has already happened? Now you just need to stop it from happening again! If you're a fleet manager and have a pump on site to refill your vehicles or machinery, we have a solution. The Piusi SB325 AdBlue™ nozzle with magnetic miss-filling spout can only release fluid into a fill point that has a partnering AdBlue magnetic tank adaptor inserted into it. With a magnetic collar fitted in the AdBlue™ fill point only, the AdBlue™ magnetic nozzle can physically not dispense into the diesel tank as there is no magnet to open the spout. Problem solved!

SB325 Nozzle

Most new vehicles and plant machinery have a magnetic collar inserted into the AdBlue™ fill point at manufacturing stage. You should be able to see whether your vehicle already has the magnetic adaptor by simply looking into the AdBlue™ fill point for something that looks like the below. If you aren’t sure then you could hold something like a screwdriver into the fill point and see whether you can feel the magnetic force. If you do, simply replacing your existing nozzle with a magnetic AdBlue nozzle will prevent the risk of AdBlue™ being miss-filled into the diesel tank.

Magnetic fill point collar

If you don’t think your vehicle has an AdBlue magnetic collar fitted you can purchase a retrofit adaptor to insert yourself, and then you can replace your nozzle with the magnetic spout AdBlue nozzle You can purchase the SB325 magnetic miss-filling nozzle or read about it in more detail here.Prevent future miss-filling buy the SB235 miss-filling spout nozzle here

Want to prevent the costly miss-filling of AdBlue into the diesel tank?

Buy the SB235 miss-filling spout nozzle here