Where did the Adblue go?

[wjamie]

I wonder if anyone knows how the adblue level is measured. My adblue indicator was sitting at about half full. This being the display on the dash when cycling through the various options. I added about 8 litres of Adblue with no issues. I believe I had topped it up all the way to full however the Adblue indicator still shows half full. Now the overall capacity of the adblue tank is just over 12 Litres so I now have a bit of a mystery as to how the gauge is still only reading half full. I have driven a few miles and stopped and started the car three times but still showing half full. Its a 2022 2.8D Active Model (Scotland). Any ideas?

 

[Andy]

My diesel transit seems to take an age to register a ‘new’ level when I fill it up too, check the gauge tomorrow!

 

[Jake the Peg]

I’ve heard stories of cheap adblue not being the correct density and the system isn’t able to recognise the top up as a result. I’d try running it for a while and topping up with a different brand

It truely is awful stuff!

 

[Dave]

It might not be the case with yours, but many ad blue tanks/meters, only measure empty, 1/4, 1/2, and 3/4, so small topups dont always register.

 

[wjamie]

Just a wee update for everyone. I posted the query on a number of forums and no one was able to advise from a technical perspective how the level of Adblue is measured. However numerous people did advise that it took a few miles or a few trips for the level to change.

In my case it increased from half full to 3/4 full after about 15 miles and then increased up to full after a further 15 miles so 30 miles in total.

 

[Grimbo]

Bit of a warning reference Jake the Pegs post ^^^^^^
All DEF or Adblue systems have a built in way of measuring the correct concentration of DEF and will go into limp mode if it's not correct .
Less of an issue with smaller vehicles but many of my customers buy it by the IBC full or 1000 litres at a go.... if stored incorrectly in full sun or outside with the lid loose it can become a cause of system faults.... I carry a refractometer to test for correct strength as a first stop diagnostic when going to a vehicle with a DEF fault , they will record it as a fault in most cases so you could read it with a code reader .
If you're tempted to buy 20l from a garage try and keep it in a dark cool place if it's not going to be used quickly

 

[Dave]

I undertand that ad blue goes off, even in a sealed container, as there is a use by date on the container. So what happens in a car that isnt used much? I have a Berlingo that holds something like 12 litres, which lasts me a good coupe of years with my low annual mileage. But no problems so far.

 

[Juddian]

In the drivers manual for MAN trucks, it mentions not to keep topping the adblu up every fill up (many companies with own fuel pumps require fuel and adblu topped up after each run), the manual says that keep topping up only a few litres at a time can lead to the system not registering adblu being used and can throw a fault.

I attended a familiarisation course at MAN head office, the trainers there stressed the same, they mentioned that the level gauge is optical, so maybe this is a typical method of on board measuring the level of the stuff.

 

[stuartjefcoate]

Just had exactly the same issue as wjamie, Adblue light came on with 1/4 tank and 900 miles left, brimmed it but it took about 40 minutes of driving and about 25 miles for the system to recognise the new level and to switch off the warning light......but it does get registered eventually.