Adblue

[yakdriver]

Trying to establish whether the use of Adblue on Audi cars (specifically A6 avant) was stopped. Seems that it does seem to be the source of a good number of problems and if models after a certain date did not use this system, I'd like to restrict my search to those. 

Thanks for any enlightenment!

[Steve Q]

Adblue seems to have a lot of problems for various manufacturers including jaguar and Ford. As long as the correct adblue is put.in.then.yiu should be ok. Funnily enough my wife has a jag xe and it needs topping up. I'm only going to put jag adblue in. Hopefully I'd like to think I'll have more of a comeback if the system says wrong adblue fitted. 

[Envy]

Been using non-Audi Adblue since the car needed it - pay less than £1/litre and get through around 10 litres every 6K miles. Purchase through Amazon with free delivery

Adblue is a urea solution and a recipe that is hard to get wrong - for you own peace of mind get Audi DEF but IMO it is an unnecessary additional expense 

[yakdriver]

Thanks for the comments - have gone with a 2014 non ad blue A6.

[jdragon]

Reviving this thread for any recent views on which type of AdBlue to use, especially with it being a contributing factor to the dreaded EGR cooler blocking aka P2002 00

My car specifically is A5 2.0 190 Ultra (DETA).

[Steve Q]

1 minute ago, jdragon said:

Reviving this thread for any recent views on which type of AdBlue to use, especially with it being a contributing factor to the dreaded EGR cooler blocking aka P2002 00

My car specifically is A5 2.0 190 Ultra (DETA).

For peace of mind on my wife's Jag I get adblue from the main dealer for peace of mind. However any of your local motor factors would be able to supply a suitable adblue. 

[Envy]

11 hours ago, jdragon said:

Reviving this thread for any recent views on which type of AdBlue to use, especially with it being a contributing factor to the dreaded EGR cooler blocking aka P2002 00

My car specifically is A5 2.0 190 Ultra (DETA).

Not sure how DEF would directly affect EGR as it is applied in the DPF way down stream in the catalytic process. I presume ineffective regen of DPF and subsequent blocking could result in backup of particulates but this would normally be flagged by more frequent regnerations.  

[jdragon]

5 hours ago, Envy said:

Not sure how DEF would directly affect EGR as it is applied in the DPF way down stream in the catalytic process. I presume ineffective regen of DPF and subsequent blocking could result in backup of particulates but this would normally be flagged by more frequent regnerations.  

That was my thought, however the Audi TSB suggests it is, along with a special driving profile which I assume means short runs.

How frequently should a DPF regen occur? My research indicates ~300 miles, and I'm seeing this around 280-320 miles.

TPI_2050077-7.pdf

[Stevey Y]

5 hours ago, jdragon said:

That was my thought, however the Audi TSB suggests it is, along with a special driving profile which I assume means short runs.

How frequently should a DPF regen occur? My research indicates ~300 miles, and I'm seeing this around 280-320 miles.

TPI_2050077-7.pdf 748.93 kB · 1 download

Hi your regeneration intervals are spot on, with regard to the adblue its not made of pigs urine which would require vast amounts of purification before use, its made of a component in the fertiliser industry which when mixed with de ionised water creates a synthetic ammonia, when subjected to extreme temperature the greater water element turns to steam and along with the ammonia turns the nitrogen oxide particles, Nox 1 into a inert particle Nox 2 which degrades rapidly in normal atmospheric conditions.

Almost all the branded adblue sold in todays market are the same and unlike fuel do not suffer with blending differences, the consumption of adblue is very dependent on fuel/oil quality I.E. if you use supermarket fuel and cheap engine oil the regeneration factor will be increased as the amount of soot produced by both is accelerated and the DPF blocks more rapidly as the soot particles will be larger and physically more dense, therefore if you use good fuel and any Quantum spec low SAPS oil you are safe, with the additive going into the fuel as long as it has a Cetane booster that raises the burn quality this promotes much smaller soot particles which burn of more comprehensively from the core filters on the DPF.

Steve.

[jdragon]

12 minutes ago, Stevey Y said:

Hi your regeneration intervals are spot on, with regard to the adblue its not made of pigs urine which would require vast amounts of purification before use, its made of a component in the fertiliser industry which when mixed with de ionised water creates a synthetic ammonia, when subjected to extreme temperature the greater water element turns to steam and along with the ammonia turns the nitrogen oxide particles, Nox 1 into a inert particle Nox 2 which degrades rapidly in normal atmospheric conditions.

Almost all the branded adblue sold in todays market are the same and unlike fuel do not suffer with blending differences, the consumption of adblue is very dependent on fuel/oil quality I.E. if you use supermarket fuel and cheap engine oil the regeneration factor will be increased as the amount of soot produced by both is accelerated and the DPF blocks more rapidly as the soot particles will be larger and physically more dense, therefore if you use good fuel and any Quantum spec low SAPS oil you are safe, with the additive going into the fuel as long as it has a Cetane booster that raises the burn quality this promotes much smaller soot particles which burn of more comprehensively from the core filters on the DPF.

Steve.

Superb explanation as always, thank you. 

The only diesel I use is Esso. And i'm using the Archoil now instead of the Millers.

Oil is either Comma Prolife 5w30 or Castrol Edge 5w30 ll. I typically change oil (drain from sump plug) and filter every 6 months, which is usually around 8-10k miles.

What are Audi referring to as "reducing agent" and if it's the AdBlue, how is that even getting back to the EGR cooler???

[Stevey Y]

1 minute ago, jdragon said:

Superb explanation as always, thank you. 

The only diesel I use is Esso. And i'm using the Archoil now instead of the Millers.

Oil is either Comma Prolife 5w30 or Castrol Edge 5w30 ll. I typically change oil (drain from sump plug) and filter every 6 months, which is usually around 8-10k miles.

What are Audi referring to as "reducing agent" and if it's the AdBlue, how is that even getting back to the EGR cooler???

Hi the term Audi use is reducing agent, it is actually adblue and the term is derived from the system our cars use which is Selective Catalytic Reduction, the system works thus, you will have three sensors before the cat one is an exhaust gas temp sensor the other is an oxygen sensor the last one is a Nox sensor of which there are two, the correct designation are upstream for before cat and downstream post cat, before all of these is what is basically a small captive shower head which when commanded by the ECU will spray adblue into the exhaust stream pre the first bank of sensors, the first NOX sensor registers the amount of Nox in the stream and the second registers the particles after the adblue spray and depending on its in formation log may request more adblue, the whole mixture is then fed into the DPF which does its thing with the soot particle entrapment, here lies the problem to make the exhaust cleaner still there is an EGR cooler at the back of the DPF which is attached to another EGR valve which when opened by the ECU at low speeds sucks the already treated exhaust gas through the cooler with drastically cools the gas to so when it is reintroduced in to the engine to be re burnt by the combustion cycle it won't be to hot which reduces combustion temps and burns any Nox 1 that escaped the first time, as I said the main culprit for the blockages is the PCV system as this adds extra engine oil vapour and water vapour neither of which burn very efficiently if at all. thats why Audi recommend longer faster journeys as at higher speeds both EGR valves are shut as the engine needs as much oxygen rich air as it can get to maintain the speed therefore it burns slightly hotter and burns off a lot of the accumulation from town/city driving.

Steve.

[jdragon]

Understood, thank you. Hence the name Exhaust Gas Recirculation valve.

It's appalling 😄

All being well I'll get more than 70k miles out of the next one.

[Stevey Y]

20 hours ago, jdragon said:

Understood, thank you. Hence the name Exhaust Gas Recirculation valve.

It's appalling 😄

All being well I'll get more than 70k miles out of the next one.

Hi I am up to 21,500 and no sign yet although I am considering changing it as I have heard good reports of extra power and drivability, got a seven hundred and fifty mile round trip in mid June so I will be making my assessment from there, yes we have gone from Euro 4 to 6 in about fifteen years and in saying that the EGR technology has improved in leaps and bounds but we still live with the problem of the sticky tar that is produced by the crankcase ventilation system I am currently researching the benefits of a Catch Tank system which apparently removes 90% of the water vapour and a lot of the engine oil solids, the only pain is draining it every week.

Steve.

[jdragon]

1 hour ago, Stevey Y said:

Hi I am up to 21,500 and no sign yet although I am considering changing it as I have heard good reports of extra power and drivability, got a seven hundred and fifty mile round trip in mid June so I will be making my assessment from there, yes we have gone from Euro 4 to 6 in about fifteen years and in saying that the EGR technology has improved in leaps and bounds but we still live with the problem of the sticky tar that is produced by the crankcase ventilation system I am currently researching the benefits of a Catch Tank system which apparently removes 90% of the water vapour and a lot of the engine oil solids, the only pain is draining it every week.

Steve.

21,500 isn't a lot. Changing what? The EGR valve/cooler?

My A4 always ran better after I had cleaned the EGR valve.

How's your other car running with 120k miles? I think you said that's a DETA like mine.

Do you have a link for the catch tank system?

 

[Stevey Y]

21 hours ago, jdragon said:

21,500 isn't a lot. Changing what? The EGR valve/cooler?

My A4 always ran better after I had cleaned the EGR valve.

How's your other car running with 120k miles? I think you said that's a DETA like mine.

Do you have a link for the catch tank system?

 

Hi my fault forgot to put the 1 in front of the 21,500, I will let you know as soon as I come up with a suitable catch tank as some I have viewed have an immediate design flaw as there is a vent on top to relieve pressure/fumes but are a primitive design and will also allow air in after the MAF which will cause no end of problems as its just like having a built in air leak which will promote excessive regenerations thus knackering the DPF in record time, I wish both our engines were as simple as the A4 but unfortunately the SCR system is a whole new ball game, you have to do the research before indulging in any mods to the existing system, just been looking for them on the net. My engine is a CNHA but believe me they are very similar with only subtle differences.

Steve.

Steve.

[jdragon]

1 hour ago, Stevey Y said:

Hi my fault forgot to put the 1 in front of the 21,500, I will let you know as soon as I come up with a suitable catch tank as some I have viewed have an immediate design flaw as there is a vent on top to relieve pressure/fumes but are a primitive design and will also allow air in after the MAF which will cause no end of problems as its just like having a built in air leak which will promote excessive regenerations thus knackering the DPF in record time, I wish both our engines were as simple as the A4 but unfortunately the SCR system is a whole new ball game, you have to do the research before indulging in any mods to the existing system, just been looking for them on the net. My engine is a CNHA but believe me they are very similar with only subtle differences.

Steve.

Steve.

I sense a new thread coming on this catch tank topic 😎

The VAG specialist firmly advised against doing an AdBlue and/or EGR delete. They said it's ok initially but when you hit the 15k mark, all manner of problems occur because the system runs hotter.

[Stevey Y]

On 5/29/2022 at 8:14 PM, jdragon said:

I sense a new thread coming on this catch tank topic 😎

The VAG specialist firmly advised against doing an AdBlue and/or EGR delete. They said it's ok initially but when you hit the 15k mark, all manner of problems occur because the system runs hotter.

Hi yes down the road when you are buying new Turbos every two years because they are burnt up and perhaps the occasional valve because they are burnt, the advent of EGR gave the manufacturer an outage on metal components for engines as they are now running 40% cooler therefore the components inside the engine don't have to withstand the thermal stresses that the older engines suffered as the old rule of thumb was the hotter they run the more efficient the burn and more power, trouble is the hotter they run the more Nox 1 they produce, everything is now designed to run cooler so the metallurgy changed with it.

 

 

Steve.

[jdragon]

Reposted here

 

Edited October 17, 2022 by jdragon