[T6] AdBlue - All Parts & Cost to replace ?

[Sasquatch]

You need a specialist, either a marque specialist or a diesel specialist who can methodically diagnose the problem instead of taking a guesswork based aim and firing a parts cannon at your expense.

Try AdBlue Diagnostics – Langley Garage if you want such a system properly looked at.

 

[Bamboo Green]

Don’t quote me on the age/life expectancy as I can’t find the place I saw that - I think it was one of the sites promoting mapping services..

As for your issue, I have recently changed my battery too (interestingly that’s another aspect of thew van that wears out after about 7/8 years) - but my AdBlue issues occurred before I changed mine.

You like me, are going down the mapping route more by necessity than choice..

Dont worry I wouldn't hold you to that with the 7/8 years!! As for batteries!! This will be my 3rd or 4th. First couple only lasted a year each!! 3rd one was on 5 years. So I effect the one I've put in is the 4th one. Got all the way through coding and the Carista said it couldn't connect it to my vehicle so it sent the report to Carista. They're looking in to it and should hear in the next few days!!

 

[Bamboo Green]

There really is some scare mongering nonsense on the internet, how is a plastic adblu tank going to die after a certain age, plastic rust?
I've had my 650 mile countdown of doom pee on my chips twice and each time the bloody thing resets before getting to zero.
The first time I did take it to a dealer and was told the adblu tank was only a quarter full and they had simply topped it up and did a normal owners reset.
The second time in France on holiday it let me down but after adding over 10 litres of supermarket adblu and driving homewards for 80 Kms the bloody thing resets and we're back in the game.
The common denominator was me being a numpty and assuming that the remaining adblu mileage shown on the dashboard display was correct when honestly I couldn't remember the last time I had topped up the tank.
My campers a 2017 model.

I was told that mine was a gen 1 adblue system so should reset itself. So tempted to drain the tank, add an decrystalize agent and ad maybe 5ltrs of adblue and go for a drive!! I did look to see if I could get under it today whilst its kn the curb!! I'm a big lad...I could get my head under. I just want to be able to check the injector make sure its clear! There's many people that have had the same as yourself Inc a friend in Wales who left his and left it and left it...then he said it just cleared!! I'm hoping mine might do the same!! I just want to rule the simple stuff out first! After sat at the top of my drive for 4 weeks though, she fired up no issues so was a win on that!!

 

[Bamboo Green]

Whichever perspective you personally choose, the demonstrable reality is 180° away from your statement.

perfectly put!!!

 

[Bamboo Green]

Hi all - in the absence of any of us having any empirical data, lets put the likelihood of people having an AdBlue issue to bed, I cannot substantiate my ‘vast majority will at some point comment’ so my-bad. Lets focus back on the goal of the post and why we have forums like this...

I’m happy to shift some of the attention to the topic @Alster and @Ayjay raised, if people feel strongly that it’s difficult for garages to easily pinpoint the cause/fix around AdBlue and thus they’re very likely will propose replacing it...

Overall - I’d really love to hear from people who either know exactly what needs to be repaired replaced when you have such an issue; or from people who have had it done and they share (a) what was involved, parts, time/effort wise and (b) what should people look to pay..

I am of the same position too tbh!! I've got to say I've picked up some decent hints and tips on this forum and helped me do little jobs much simpler than first imagined, plus also enabled me to say..."book it in thats far easier", or I've got to buy more tools!

 

[ben5560]

So not on a T6, but my Q5 is having issues with it's adblue system after all I did was top it up.

I have changed the pump, pressure sensor (after reading it was showing -153hpa) and dropped and cleaned the tank. Nothing has worked. Not even Audi can clear the fault, and their only solution is 'new tank' but can't tell me why. Now the new sensor reads -3hpa, they are recommending I drive at least 100km to reset the system which I have yet to try. A new tank from Audi here is 2500 EUR... And it's not in stock even in Germany!

They also reckon it can be tripped by even a low battery, so tried changing that as well.

 

[Ayjay]

@ben5560 - I was in the same position with my 2014 Q5 in that there was an adblue fault but my Audi dealer (who, to be fair, was usually very good indeed) were unable to identify the cause and were talking about potentially changing the whole adblue system in stages to sort it out (and, even then, were not prepared to make any promises!). In the end, I went against all my instincts and had adblue deleted, IIRC at a cost of about £200. That was 4 years ago and it's passed every MOT and associated emissions test since (I believe HU (TÜV) is your equivalent to our annual MOT test). I've also had an ongoing issue with my T6 with what seems to be the usual incorrect range warnings and which VW seem incapable of resolving but I'm reluctant to go down the deletion route.

 

[ben5560]

@ben5560 - I was in the same position with my 2014 Q5 in that there was an adblue fault but my Audi dealer (who, to be fair, was usually very good indeed) were unable to identify the cause and were talking about potentially changing the whole adblue system in stages to sort it out (and, even then, were not prepared to make any promises!). In the end, I went against all my instincts and had adblue deleted, IIRC at a cost of about £200. That was 4 years ago and it's passed every MOT and associated emissions test since (I believe HU (TÜV) is your equivalent to our annual MOT test). I've also had an ongoing issue with my T6 with what seems to be the usual incorrect range warnings and which VW seem incapable of resolving but I'm reluctant to go down the deletion route.

Oh I'm just living over here mate, British too

But yes, same issues - they can't say what it is and don't bother trying to change out components and read the data, their answer is 'new tank' and not say why!

So I'm leaning towards a delete as well just to get it over and done with... Instead of 2.5k+! Guy at Audi said he knew someone who changed the tank and even that didn't fix it, it came back and it just turned out to be the battery - couldn't explain why though!

 

[Graham Newport]

Had the dreaded 650 miles left Adblue warning come up yesterday. When I last used the van six day’s ago I had 3500 miles left to run. Topped up with 5Lts and added wins aditive to prevent crystalIization. Carried out the reset procedure with no change on the level. After driving under a mile it dropped down to 600 miles left to run. I checked I had plenty of Adblue by removing the top hose on the side of the Adblue tank. The Adblue was at this level. Which is just over 3/4 full.I have driven 55 miles today and still showing 600 miles. My van is 2019 with 31000 miles on the clock. Had a word with a mechanic and he has come across this problem a few times. He said it might need a new Adblue tank. Finger crossed it’s not the dreaded Adblue tank

 

[bluezie]

Am I being too simplistic here, but surely if the tank level sensor is reporting incorrect and erratic level readings, it's the no. 1 suspect to look at? I.e. remove it, clean it, and check for any crystalline build-up in the tank obstructing the sensor's operation. Then using the measuring blocks in the diagnostics, test the sensor's output readings, if erratic, renew the sensor.
Or, why is diagnosing these systems so complicated, that most garages just replace the whole tank? It'd be interesting to have some technical background on this system if anyone knows exactly how it all works, and why it's such a problem with diagnostics.

 

[Sasquatch]

Its not complicated with rhe correct equipment and training - its just most garages have neither the correct equipment of training. The outfits that specialise in this sort of thing manage it just fine.

 

[StratosFearXX]

Am I being too simplistic here, but surely if the tank level sensor is reporting incorrect and erratic level readings, it's the no. 1 suspect to look at? I.e. remove it, clean it, and check for any crystalline build-up in the tank obstructing the sensor's operation. Then using the measuring blocks in the diagnostics, test the sensor's output readings, if erratic, renew the sensor.
Or, why is diagnosing these systems so complicated, that most garages just replace the whole tank? It'd be interesting to have some technical background on this system if anyone knows exactly how it all works, and why it's such a problem with diagnostics.

I'm assuming that tank and sensor are all one 'part'?

 

[ben5560]

In the Q5 at least, the level sensor uses ultrasonic and is situated next to the pump and pressure sensor.

In older versions you could remove the entire module which houses all this, newer ones it's a sealed unit. Not sure about the T6 though.

And yes Audi will just read it and their Guided Fault Finding software will say 'new tank' but not why.

I have spent 700 just fault finding, changing individual components and still nothing so maybe that is why, instead of messing around they just change it all. But when I read the data, the pressure sensor was reading -153hpa, which is not right. Then apparently AI says that means the system will not start the pump, and therefore it's kind of a software lock.

Stupid software, stupid system all just for emissions.

 

[Graham Newport]

Had the dreaded 650 miles left Adblue warning come up yesterday. When I last used the van six day’s ago I had 3500 miles left to run. Topped up with 5Lts and added wins aditive to prevent crystalIization. Carried out the reset procedure with no change on the level. After driving under a mile it dropped down to 600 miles left to run. I checked I had plenty of Adblue by removing the top hose on the side of the Adblue tank. The Adblue was at this level. Which is just over 3/4 full.I have driven 55 miles today and still showing 600 miles. My van is 2019 with 31000 miles on the clock. Had a word with a mechanic and he has come across this problem a few times. He said it might need a new Adblue tank. Finger crossed it’s not the dreaded Adblue tank

I give the van a short drive to see if by magic the dreaded adblue fault had put its self right. No such luck and it drop down to 550 miles left to go. I have driven about 50 miles from when I had a 600 miles left to run. So some how it can still manage to know how I have used 50 miles worth of adblue. What a sh-t method VW use to monitor adblue level. I have book the van in on Friday with a very knowledgeable Technician I had recommended to me.

 

[Sasquatch]

What a sh-t method VW use to monitor adblue level.

I believe they use an ultrasonic sensor at the top of the tank.

 

[Ayjay]

I believe they use an ultrasonic sensor at the top of the tank.

At the risk of contradicting my learned friend above, I understand the ultrasonic sensor is at the bottom of the adblue tank and is supposed to read where the surface of the adblue is. It’s when crystals form on the surface that the readings get inaccurate and you get false warnings. Maybe that would also explain why they insist on changing the whole tank as the sensor is integral to it and can’t be easily accessed. That and VW can’t be arsed when they can fleece you with a much bigger bill replacing the whole system. Oh I also forgot it’s a crap design as well.

 

[ben5560]

Yeah it's a completely shit design. They used to be removal modules which could be replaced, now they aren't and they charge stupid money for the whole thing

 

[Alster]

It’s the same in my trade - you used to be able to replace the bearings in a washing machine quite economically. Now they glue the tub together so you have to replace the whole tub and drum assembly which effectively rights off the machine.

 

[Sasquatch]

At the risk of contradicting my learned friend above, I understand the ultrasonic sensor is at the bottom of the adblue tank and is supposed to read where the surface of the adblue is. It’s when crystals form on the surface that the readings get inaccurate and you get false warnings. Maybe that would also explain why they insist on changing the whole tank as the sensor is integral to it and can’t be easily accessed. That and VW can’t be arsed when they can fleece you with a much bigger bill replacing the whole system. Oh I also forgot it’s a crap design as well.

You are probably right on the sensor location.

VW aren't alone in making tank, sensor, etc integral. Virtually all manufacturers do, many including the pump as well. It makes assembly easy and less expensive on the production line with the obvious consequences for the wallet of the owner of a broken van.

 

[Graham Newport]

I give the van a short drive to see if by magic the dreaded adblue fault had put its self right. No such luck and it drop down to 550 miles left to go. I have driven about 50 miles from when I had a 600 miles left to run. So some how it can still manage to know how I have used 50 miles worth of adblue. What a sh-t method VW use to monitor adblue level. I have book the van in on Friday with a very knowledgeable Technician I had recommended to me.

The sensor is now reading correctly after my visit to the knowledgeable technician. He has done a reset informed me he carried out a reset for the same problem on a t6 18 months ago and has been working ok since. He did say use Adblue additive when topping up to help prevent cystallization in the future.