Does adblue go off.

[Jim Rey]

Does adblue go off?
I bought a 10L of Redex adblue in July this year and used 8L (production date june 22. Approximately 2Litres left. I bought Greenchem 5Ltr Ad Blue (production date Oct 22 to keep in the garage.
I know adblue is a mixture of urea and deionised water.
I notice a smell form the remaining Redex adblue container but the Greenchem stuff has zero smell. Is the first one going off or is it the space in the first container collecting uric acid vapour?

 

[Loz]

I think it lasts 12 months but It crystallises, so just check it before you use it.

 

[Ali-G]

The stuff I've got in the garage says that it should be used within 18 months of the date of manufacture.

 

[Rioja John]

Can it go off in your van as My T6.1 has a adblue tank which holds enough for 16,000 miles plus, my van is now 15 months old 4000 miles on the clock and the display says ok for another 14,000 miles it will take me another 3 years at least to use the adblue that was originally put in my van so it looks like it will be 4-5 years old when it will need topping up.

John.

 

[TheOldGoat]

I don't know about adblue going off as such.
However I've just had the adblue warning on the instruments warning that the engine will not
start in 650 miles due to adblue fault.

After the dash warning I assumed the tank must be very low, I've only filled it once in 14,000 miles.
So I bought a 10l drum and went to top up. I only got 6 litres in and flooded the tank!

The main dealer diagnosed a faulty adblue quality sensor, this is part of the adblue tank
and it seems is not replaceable without fitting a new tank.
So I had a new tank fitted, (warranty work). Because of this they said they had to test the adblue in the tank.
The result was a reading of 27% on a refractometer, and the requirement is 32%.

The dealer suggested that my adblue was poor quality, so I explained the fault appeared before I topped up.

When I picked the van up I asked the technician to test the reamaining stuff and it was 32.5%.!

Now, I suspect the sensor was faulty but they tested the contents of tank at 27% so maybe not?
Perhaps the stuff had gone off. But how? Does anyone know if it can evaporate? I would expect the distilled \ de-ionised
water to evaporate first, increasing strength.


If you have access to VCDS then you can see value of quality from the engine blockmap.
Search for "urea" and you will find something like:-
IDE10032,Reducing agent quality sensor: urea concentration,32.79, %
IDE10039,Reducing agent quality sensor: validity,invalid,

This was from an earlier scan, perhaps showing sensor was faulty?

On the scan I did after the fault appeared in the insruments the quality was down to 25%.

Faulty sensor or crap adblue? Who knows.

 

[Jim Rey]

I don't know about adblue going off as such.
However I've just had the adblue warning on the instruments warning that the engine will not
start in 650 miles due to adblue fault.

After the dash warning I assumed the tank must be very low, I've only filled it once in 14,000 miles.
So I bought a 10l drum and went to top up. I only got 6 litres in and flooded the tank!

The main dealer diagnosed a faulty adblue quality sensor, this is part of the adblue tank
and it seems is not replaceable without fitting a new tank.
So I had a new tank fitted, (warranty work). Because of this they said they had to test the adblue in the tank.
The result was a reading of 27% on a refractometer, and the requirement is 32%.

The dealer suggested that my adblue was poor quality, so I explained the fault appeared before I topped up.

When I picked the van up I asked the technician to test the reamaining stuff and it was 32.5%.!

Now, I suspect the sensor was faulty but they tested the contents of tank at 27% so maybe not?
Perhaps the stuff had gone off. But how? Does anyone know if it can evaporate? I would expect the distilled \ de-ionised
water to evaporate first, increasing strength.


If you have access to VCDS then you can see value of quality from the engine blockmap.
Search for "urea" and you will find something like:-
IDE10032,Reducing agent quality sensor: urea concentration,32.79, %
IDE10039,Reducing agent quality sensor: validity,invalid,

This was from an earlier scan, perhaps showing sensor was faulty?

On the scan I did after the fault appeared in the insruments the quality was down to 25%.

Faulty sensor or crap adblue? Who knows.

Thanks for that info. Sometimes I wish I had a petrol van

 

[DaveCrampton]

If adblue starts to crystallize then it is because it is sat still in you garage. Impurities in the solution will be a seed for the chemical to form a crystal around.
If your adblue is in the van, and you are driving it, then the movement of the liquid solution will prevent crystallization starting.

 

[Jim Rey]

In Braemar this morning it was -15C . I've heard adblue freezes at -11C. What would happen to the adblue in the van I wonder

 

[Robert]

In Braemar this morning it was -15C . I've heard adblue freezes at -11C. What would happen to the adblue in the van I wonder

That is correct, Adblue freezes at -11.5°C in the tank.
At the suction point there is a "kind of special chamber" which has a heater built in.
This allows frozen Adblue to melt down before it is taken into the system.

 

[Jim Rey]

That is correct, Adblue freezes below -11°C in the tank.
At the suction point there is a "kind of special chamber" which has a heater built in.
This allows frozen Adblue to melt down before it is taken into the system.

This is the sort of information that makes membership of this forum so worth it. Thanks.

 

[DaveCrampton]

It also depends on where you park? I park my Passat next to my house with the driver's door closest as when it freezes the door lock will not close when I close the door. Parking close to the house affords some protection from frost and I find that side does not have frost on it in the morning.

 

[Jim Rey]

I spray a light coating of WD40 around all the door seals and the door handles this helps them open easily the next day after a hard frost