What is Adblue?
AdBlue is a marketing name for a urea-based ‘Diesel Exhaust Fluid’ that is used to help convert diesel exhaust emissions into less harmless chemicals.
AdBlue and other Diesel Exhaust Fluids are made from a mix of deionised water and automotive grade Urea in a specific ratio.
Why do cars need it?
Emissions regulations for vehicles continue to get tighter and tighter and to keep up, engine and vehicle manufacturers have found two ways to make diesel engines comply, those being DPF systems and DEF systems.
The most damaging component of diesel exhaust emissions is Nitrogen Oxides. NO, and NO2 are collectively referred to as NOx and are a primary concern for diesel engine manufacturers.
NOx differs from N20, otherwise known as laughing gas and light sedative which is considered safe for humans and around foods.
We covered DPF systems in a previous article, and here we’ll take a look at Diesel Exhaust Fluid systems and how they work.
How does it work?
AdBlue is stored in a dedicated tank, entirely separate from the fuel system, and is metered into the exhaust at specific quantities. The heat from the exhaust converts the Urea into Ammonia, where it reacts with Nitrogen and converts the nitrogen oxides into harmless water vapour and pure Nitrogen.
Typically a full tank of DEF will last 12,000kms or more, depending on your driving style and towing habits, and when the level starts to become low, an indicator on your dashboard will light up to remind you to top up the system.
Due to regulations, it’s no big deal if you run out of DEF while driving, although keep in mind your vehicle will refuse to start once stopped unless you at least partially refill the AdBlue tank and ensure that the emissions systems are operational again.
Can I just pee in the AdBlue tank?
No, urine contains only around 2% urea, compared to 32.5% in commercially available DEF such as AdBlue. The sensors in your vehicle will detect the correct ratio of urea isn’t present and will disallow starting the engine.
It is very important not to accidentally put AdBlue into the diesel tank, and likewise, putting Diesel into an Adblue tank can have disastrous consequences.
Adblue is corrosive to most fuel system components, and if the vehicle has been running after the system is contaminated, the entire fuel system will likely require replacing. Everything from the fuel pump, fuel lines, fuel injectors and more will require replacement.
If you realise you have put the fluid into the wrong tank, it is very important not to start the vehicle and to call a tow truck. The tanks will need to be professionally drained, cleaned and the contaminated fluid disposed of correctly.
Donnellans are your friendly mechanical, tyre and wheel specialists.
For all your vehicle maintenance, servicing, fluid level checks and fuel system inspections, come see the friendly team at Donnellans the Tyremen.
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