Ad Blue - remove or treat ?

[Hawthorn37]

I’ve read the many posts on here about the costly effects of Ad Blue crystallisation, and want to avoid it.

We’re doing fewer miles in our Cali this year, and I’m aware the last time I filled the Ad Blue tank was over 12 months ago. After the refill it gave 18,500 miles range. Currently the van has 15,000 miles Ad Blue range (which sounds about right).

My questions are:
1. At what point does Ad Blue become an issue re crystallisation? What is “too old” ?
2. Is adding a bottle of additive sufficient to keep it healthy?
3. Should I siphon out the old Ad Blue and replace with (a smaller volume ) of new Ad Blue? Is this okay to do - or will it it mess up the engine management or something?

Many thanks.

 

[Perfectos]

#1 see photo attached
#2 Probably not - see #1
#3 The van should see the volume has changed, the tank level sensor should "check" the ad blue level upon turning the ignition on.

Is it best to have a full tank of ad blue or partial tank with air gap ?
TBH I think the ad blue issues are a bit of a lottery, given the number of vehicles on the road, all manufacturers have issues with the systems and there is a whole industry sprung up to fix the issues caused by ad blue in vehicles. Im not sure there is a definitive answer to the issue.


Additional info

AdBlue Tank Flush: When to Drain & Refill | Step-by-Step

When an AdBlue tank flush is needed rather than a top-up, the full drain and refill procedure step by step, and what to check if the warning returns.

adbluespecialist.co.uk

Expert Guide- Small AdBlue Diesel Drain Procedure

24/7 Nationwide AdBlue in Diesel Tank Rescue: 07459 909935National AdBlue Drain Rescue: https://www.adblue-in-diesel-tank-specialist.co.uk/If you found this page, we cover you!Nothing derails a schedule faster than unexpected operational downtime, especially when it involves modern selective...

www.adblue-in-diesel-tank-specialist.co.uk

 

[Hawthorn37]

#1 see photo attached
#2 Probably not - see #1
#3 The van should see the volume has changed, the tank level sensor should "check" the ad blue level upon turning the ignition on.

Is it best to have a full tank of ad blue or partial tank with air gap ?
TBH I think the ad blue issues are a bit of a lottery, given the number of vehicles on the road, all manufacturers have issues with the systems and there is a whole industry sprung up to fix the issues caused by ad blue in vehicles. Im not sure there is a definitive answer to the issue.

View attachment 152391
Additional info

AdBlue Tank Flush: When to Drain & Refill | Step-by-Step

When an AdBlue tank flush is needed rather than a top-up, the full drain and refill procedure step by step, and what to check if the warning returns.

adbluespecialist.co.uk

Expert Guide- Small AdBlue Diesel Drain Procedure

24/7 Nationwide AdBlue in Diesel Tank Rescue: 07459 909935National AdBlue Drain Rescue: https://www.adblue-in-diesel-tank-specialist.co.uk/If you found this page, we cover you!Nothing derails a schedule faster than unexpected operational downtime, especially when it involves modern selective...

www.adblue-in-diesel-tank-specialist.co.uk

“Is it best to have a full tank of ad blue or partial tank with air gap ?”

That’s what considering. I’ve read about overfilling issues, but if the tank has a low level, would that promote crystal growth on the walls ??

 

[dspuk]

“Is it best to have a full tank of ad blue or partial tank with air gap ?”

That’s what considering. I’ve read about overfilling issues, but if the tank has a low level, would that promote crystal growth on the walls ??

From what I read the biggest issue is cold.

Keeping it as full as possible will mean the cold should affect it less.

 

[Perfectos]

My research: Heat is a real problem for storage, above 20 degrees C it goes off and crystallises rapidly.

The system has heaters to deal with cold conditions. Repeated freezing appears to cause crystals

It's a Goldie locks system !

 

[temporarysecretary]

So definitely don't buy it from those petrol forecourts where its sat outside.

The temperature window is interesting. My Vauxhall work van says in the owners manual not to fill up the ad blue when its below 11 degrees C. In the winter we drive round with it in the footwell to warm it up first as they are also plagued with adblue issues.

 

[Hawthorn37]

So maybe the best plan is to siphon most of it out; buy new Ad Blue from somewhere with fast moving stock (say Halfords or Costco) - but still checking the manufacturing date; condition the container to around 15-18 degC; refill when the ambient temperature is okay; get the tank to almost full but don’t overfill.

Half my brain thinks this would be wise, the other half “if it ain’t broke, don’t fix it”