AdBlue Discussion and Issues

[Stevefrs]

The level sensor may not see the level dropping and throw a fault code. Secondly if it has been submerged it is possible that as the adblue is used and residue adblue will crystallise over the sensor which again may not be able to see the level dropping.
Sure when I picked my caravelle up there was a separate advice note on filling.

 

[Paynewright]

The VW reasoning for not over filling is on this thread..

"air gap" lol nonsense, I've been filling this for 50 k miles and I do the same with my Transit , no problems

 

[Pete C]

What are the issues with over-filling the tank??? Last time, I just brimmed it, like putting fuel in

Several threads on this. Sensors struggle to identify AdBlue level, and system fails.
Never put in more than the dash readout says - there’s a reason it states a maximum amount to add.

Pete

 

[Markgf]

I’ll take a bit more care in the future. Cheers all.

 

[Village]

Yeah i totally ignored all the advice on my first refill, after all, how hard can it be, right?! I brimmed it and it refused to register, so then actually read the advice, and had to syphon a load of it out which was pretty vile!

 

[Broadside]

Yeah i totally ignored all the advice on my first refill, after all, how hard can it be, right?! I brimmed it and it refused to register, so then actually read the advice, and had to syphon a load of it out which was pretty vile!

I’ve never had an issue with my van fortunately but I had been wondering about people that do overfill and if syphoning or pumping out the excess would clear the problem rather than having a garage repair.

It’s good to know that it worked for you.

 

[Markgf]

I think, from memory, mine was getting low, I just kept pouring, until the can ran out, but didn’t fill the tank. Maybe I lucked in!

 

[benp1]

I did it only just this morning;
Purchased 5L Adblue from Costco last time we were there.
Display showed;
View attachment 59561
Swapped units to metric.
View attachment 59562

Poured in the 5L job done.

Once you know that info you wait until the 1500m warning comes up and just pour in 5L

What gallons are they using? 1 imperial gallon is 4.55 litres. That's the equivalent for miles to km. How does 1 gallon equal 3.5l, and 1.75 gallons equal 7 litres? I get the advice to leave to some air, but on their calculations, that's still quite a big margin of error

 

[peterposh]

Fill it to the brim, you won't have any problems

 

[dubber36]

What gallons are they using? 1 imperial gallon is 4.55 litres.

It will be whatever UNITS you have set in your DIS.

Ad Blue containers are generally marked in litres, so to save any confusion, I change the UNITS to metric for the purpose of this job.

 

[benp1]

It will be whatever UNITS you have set in your DIS.

Ad Blue containers are generally marked in litres, so to save any confusion, I change the UNITS to metric for the purpose of this job.

I get that. But if it's instructing you with the volume to fill, and it can display it in units of your choice, the volume should still be the same. it's not. So struggling with their advice to leave an air gap when the range is so big, unless they're very conservative in their estimate

I converted gallons to litres on an imperial basis when I needed to fill up with adblue, and it was fine. But their own conversion approach seems bonkers?

 

[Grim Reaper]

Fill it to the brim, you won't have any problems

This is the second time you've advised this that I've seen and I'm going to rebuke you once more.. DO NOT FILL THE ADBLUE TANK TO THE BRIM! THE SENSOR NEEDS AN AIR GAP ABOVE THE FILL LEVEL IN ORDER TO WORK, FILLING TO THE TOP OF THE FILLER NECK MEANS THE ULTRASONIC SENSOR CANNOT SEE A REFLECTION FROM THE SURFACE AND CAN CAUSE ISSUES JUST AS BAD AS IF YOU HAD LET IT RUN DRY.
STOP ADVISING PEOPLE TO TOP THE ADBLUE TANK TO THE BRIM.
ONLY PUT IN AS MUCH AS THE DASH READOUT ADVISES (IF NOT A LITTLE LESS TO BE SURE) AND TOP UP MORE OFTEN, IT'S NOT LIKE YOU DO IT EVERY WEEK.

 

[Stevefrs]

Advice from the handbook relating to filling

 

[Pete C]

Fill it to the brim, you won't have any problems

This is not what the manual says. People doing this have had problems.

Pete

 

[Kind of Blue]

This is the second time you've advised this that I've seen and I'm going to rebuke you once more.. DO NOT FILL THE ADBLUE TANK TO THE BRIM! THE SENSOR NEEDS AN AIR GAP ABOVE THE FILL LEVEL IN ORDER TO WORK, FILLING TO THE TOP OF THE FILLER NECK MEANS THE ULTRASONIC SENSOR CANNOT SEE A REFLECTION FROM THE SURFACE AND CAN CAUSE ISSUES JUST AS BAD AS IF YOU HAD LET IT RUN DRY.
STOP ADVISING PEOPLE TO TOP THE ADBLUE TANK TO THE BRIM.
ONLY PUT IN AS MUCH AS THE DASH READOUT ADVISES (IF NOT A LITTLE LESS TO BE SURE) AND TOP UP MORE OFTEN, IT'S NOT LIKE YOU DO IT EVERY WEEK.

Hello,

I am very loathe, to disagree with anyone on this issue of AD-BLUE filling one way or an other. I appreciate, that most have far more technical knowledge and experience than I on this issue. I would be most cautious and hesitant to advise anyone to follow contradictory advice. However, I can say that my own experiences of following most of the advice written in the handbook except to the point, on each occasion I filled to the absolute brim, I had seen absolutely no problem at all. That is, at least, so far as my very limited technical knowledge on the matter allows me to say.

Obviously some are having problems, perhaps with not following the exact procedure to the very letter, no more no less. Perhaps I may have undermined the integrity of the equipment in some other unseen way be being over generous and anxious to fill to the brim, time may tell. Perhaps the gentleman, advising contrary advice, may also have seen no ill effects either. What does seem evident is that some have problems with ad blue what ever they do, regardless, of following instructions explicitly or not.. I would also go as far to suggest, that the design of the device or ad blue tank seems deficient to my mind, in that it allows overfilling, in the first place. If it is so sensitive to inevertable clumsy filling it needs to be fool proof or driver proof.

 

[Grim Reaper]

Would it be cynical of me to suggest that the current system is a revenue producing item for those times that the advice in the manual is not followed? VW need to keep the money rolling in somehow... EGR / DPF / AdBlue / Combined Pressure sensor/Glowplug. They are all engine stoppers if not maintained correctly or replaced when they go faulty.

 

[Robert]

And my input to the topic









Above is from self study document based on the Passat but this generation of SCR system on Passat 2016 is the same as T6.

And the conclusion is only one!
There is no max limit for filling adblue and MFD max quantity is only indicative guidance.
I am not advising anybody but I fill my adblue tank to absolute maximum every time it requires top up and I have never experienced any issues.

Complete PDF document below.

Self Study Program 540 - SCR Exhaust Gas Treatment in the Passat 2015 - PDF for FREE

VAG SSP 540. This Self-study Programme will provide you with information about the new features of the SCR system using the Passat 2015 as an example. Across the globe, lawmakers and authorities are progressively lowering the limits for nitrogen oxide levels in motor vehicle exhaust gases. One...

procarmanuals.com

 

[Grim Reaper]

From your picture..." The ultrasonic waves are reflected by the boundary layer between the reducing agent and the air." .. So, tell me again how your method is correct?

 

[Robert]

I don't need to support my statements again all evidence is there already .
Have a read the self study program 540

 

[Stevefrs]

And I will continue to follow the manual and fill with the amount the mfd says to max fill.
Don't want any wiggle room for the dealer saying "oh you overfilled it hence the fault..."