[rmcgarrity78]

I Just recently had my 2010 Touareg TDI serviced, a couple of weeks later the ad blue light comes on with 450 mile count down, this was strange and i figured that the VW dealer didn't top off my ad blue during its service. I returned the car to the dealer, after further inspection they said the ad blue was full, but there was a bigger issue where there was crystallization throughout the ad blue system. The dealer advised that the entire ad blue system need to be replaced at a cost of 4k. This came as a shock to me. Their reason was that the the ad blue was contaminated and caused the crystallization. The car has had its last 2 services at this dealer and i find it hard to believe that this wasn't picked up earlier, the car was also second hand, but its prior service history had been with a VW dealer. They tried to cover it with my fidelity insurance, but fidelity claimed that contaminated fluid inst part of normal wear and tear and declined the claim. So now i want to push pack on Fidelity to try and have them cover the claim otherwise its off to VWOA to get a resolution. If anyone has experienced something similar or has any knowledge to the following questions it would be greatly appreciated:

1: I thought all Ad Blue was just ammonia and water, how would one ad blue fluid to another cause contamination?
2: Is there away of cleaning the crystallization from the ad blue system with out replacing it?
3: If i never got a warning light that the DEF/Ad Blue was contaminated, isn't that malfunction of the car itself and therefore be covered by the fidelity warranty?
4: Is 4k a reasonable cost to replace the ad blue or are they trying to take advantage?

Thanks
RMcgarrity78

 

[Black Grouse]

Adblue is an aqueous urea solution made with 32.5% synthetic urea and 67.55 de-ionised water. It can become contaminated and/or crystalised if it's stored badly or if containers are left unsealed. If all additions of Adblue have been made at VW dealers, I guess you need to press VWoA.

 

[Philth]

I wonder if they left the filler cap off/loose on the AdBlue tank from the last service? Hard to say now. They've already looked at it and probably covered it up, if so.

I haven't read about this being a common issue. Something happened and since it was serviced by VW using VW fluids, I'd push hard for VWoA to pay for the bill.

 

[Philth]

BTW - $4k is attrocious. The parts probably are somewhere around $1k, if that. Let me check.

 

[Philth]

I'd say around $1,500 in parts, roughly looking at things. Depends on how much they are replacing? All of the lines and injector too? Not much more, but the tank assembly with everything in it has an MSRP of something like $1,025.

 

[rmcgarrity78]

Thanks for your response. I have asked VW to provide me an exact breakdown of what they want to replace on the ad blue system, but based on your estimate, we can roughly say $2,600 parts and labor. This is a great help! I have a claim in with VWOA goodwill. I will push to have them cover the cost.

 

[rmcgarrity78]

VW is now saying fluid is not contaminated. its crystallized and for them to check for crystallization they would need to remove either tank or exhaust. They also said that any part that comes in contact with ad blue liquid would need to be replaced as it is compromised. so the whole system would need to be replaced. The saga of BS continues...

 

[Philth]

VW is now saying fluid is not contaminated. its crystallized and for them to check for crystallization they would need to remove either tank or exhaust. They also said that any part that comes in contact with ad blue liquid would need to be replaced as it is compromised. so the whole system would need to be replaced. The saga of BS continues...

The lines are easy to check. Just blow air through them to see if there is blockage.

 

[noobytoogy]

Has anyone found a way to recode the DO NOT RESTART ENGINE signal that an empty ad-blu tank sends out?

If so, what are the consequences of not using ad-blu at all?

And, no, I'm not interested in the ethics of this at all, especially given VW's idea of "ethics"!!

Just, is it a practical proposition if it is possible to switch ad-blu off?

Is there anything mild that could dissolve the crystallised pig piss to clear the system?

 

[hydrolocked]

Urea is very water soluble, so distilled water and time should be good enough.

 

[Black Grouse]

Has anyone found a way to recode the DO NOT RESTART ENGINE signal that an empty ad-blu tank sends out?

If so, what are the consequences of not using ad-blu at all?

And, no, I'm not interested in the ethics of this at all, especially given VW's idea of "ethics"!!

Just, is it a practical proposition if it is possible to switch ad-blu off?

Is there anything mild that could dissolve the crystallised pig piss to clear the system?

Given that Euro 5 Touaregs fitted with Adblue didn't prevent the engine restarting AFAIK, as it's only a requirement under Euro 6, then I don't see what harm an over-ride would cause.

It's suggested that some manufacturers reduce Adblue injection rates when not in test mode - but I've not seen credible evidence to support that.

 

[noobytoogy]

Urea is very water soluble, so distilled water and time should be good enough.

Reading up elsewhere there is a suggestion that sensors work out if someone isn't using pig piss for real and water on its own buggers up these sensors.

Quite why it would do that rather than send a report to the MDF to flash up a "Find the nearest pig" message I do not know!

 

[Black Grouse]

Reading up elsewhere there is a suggestion that sensors work out if someone isn't using pig piss for real and water on its own buggers up these sensors.

Quite why it would do that rather than send a report to the MDF to flash up a "Find the nearest pig" message I do not know!

It probably measures NOx levels in/out of the SCR - if the required reduction doesn't occur it could trigger a fault.

 

[Fourdiesel]

Urea is very water soluble, so distilled water and time should be good enough.

Agreed. Even if considerable evaporation has occurred (and it's hard to see how this can occur in a closed system) having crystals precipitate is difficult. I doubt seriously that:
1) there is any urea precipitation
2) if there are crystals it is certainly from contamination from something that should NOT have been added. This points directly to previous additions by an 'authorized dealer'. If rinsing with water does not remove the co-called 'crystals' then that is proof it is NOT urea. A simple test.

The reason for using urea is that it disassociates when heated to form ammonia and water. The ammonia is necessary to react with the NOx to form Nitrogen (gas) and water. Ammonia is not present until the solution is heated to exhaust gas temps in the SCR converter.

According to Wikipedia the solubility of urea varies from 1079 g/L @ 20 degC to 4000 g/L @ deg 80C. The out-of-the bottle concentration of AdBlu is 30% or 300g / L[1000g]. @ 20 degC one would have to evaporate more than 2/3 of the water before one could BEGIN to see crystals.

 

[Marbles]

Just went through this in my 09 took 4 weeks to get it done though. After 70k mile service and fill up with DEF and within a couple of day warning of no restart in 450 miles. Took it in to get looked at and the dealer blames the fluid. They replaced the adblue pump 7L6-198-970-A ($311) the controller for the pump due to updated pump 7N0-941-329 ($247) and the tank repair kit 561-198-969 ($500) which is everything inside the tank. They claim all is fixed and to pick it up, well within 50 miles the range warning is back and so is the CEL for P20EE and P207F. They claimed residual fluids causing this in a system that only goes one way to the injector and couldn't get the dealer level computer to reset the warning so they uses Vag-com rosstech to reset it and then have me pick it up. We I made it about another 50 miles and guess what the CEL is back on for the same codes then the no restart in 450 miles is back. Take it back and they then contact VW tech support that informs them they needed to update the ECU due to the newer pump controller. After a few days and many test drives they say it done and come pick it up, well it never made it out of the service bay before the light was on again. This time they swear it the rear NOX sensor ($700) and claim that VW tech support suggests to replace it. Finally pick it up and have not seen the CEL lights or warning no restart yet, but it's only been a day and less than 100 miles.

Moral of all this look into the exhaust delete by rawtek or buzzken and a tune to get rid of the whole system. If my warranty didn't cover it that was my plan. Definitely cheaper than the replacement of parts

Cost to me was $50 deductible and $39 for Urea at the stealership.
My extended warranty pay over $2400 for the repairs and I had to drive a Jetta for a month.

If you have them replace the pump and controller make sure they update the ECU as there is not a technical service bulletin for it.

Yes the DEF will crystallize, and is easily clean with hot water and compressed air as my nozzle was crustly at the 70k service so I took it out and soak in water and them blew it dry. Also the parts that were returned to me have caking on them especially the in tank assembly that had only been in for maybe a little over a year and less than 20k miles.

 

[Marbles]

Here is the nozzle picture

 

[Oregon TDI]

what are the consequences of not using ad-blu at all?

It seems logical that this would not be good for AdBlue fluid pumps. It would be like operating your windshield washer when the reservoir is empty. Except a lot more expensive when the AdBlue pump fails after "running dry".

 

[noobytoogy]

So the fix needs to switch the pump off as well as deleting the "Turn the engine off" signal.