2.0 TDi Ultra CNHA EGR and cooler removal and cleaning

[orion1210]

Hi,

Our 2014 A6 ultra, with 105K on the clock, keeps posting a 19226 P2002 Particulate Bank 1 Efficiency Below Threshold fault code.

The DPF appears ok on VCDS, both load wise and regular re-gens, and I have also swapped the two differential pressure sensors and re-adapted which hasn't changed anything.

I've read that the EGR system, in particular the EGR cooler can become clogged over time and so would like to attempt to clean them out to see if it makes a difference.

I've had a look on youtube and other forums for a guide but am struggling to find this engine. The HP EGR, LP EGR valves and cooler look absolutely buried by the turbo, can anyone offer any advice on how to tackle this job?

Thanks

[A8Cruiser]

Can you post up a photo of the location of the EGR?

[TheRenegade]

I've got a new EGR waiting to go in as mine seems to be causing me no end of problems. The Bank 1 error seems to come up almost every time. I've done some work on my A6 (also CNHA) myself but looking at this, it seems the cooling will need to be drained. I've got the workshop manual but it still seems like a difficult job.

[orion1210]

36553

I'm told it's among/below this lot.

[TheRenegade]

If i'm not mistaken, it's further towards the back and on the bottom half of the DPF. I'll see if I can find a picture.

[TheRenegade]

Looked at the parts catalogue as it shows where it goes on...this is what I found

36554

[orion1210]

Cheers, the attachment link won’t open, but it might be my phone.

Do you think pulling the arch liner and going in from the side might be the best route?

[Tripletrouble]

I may be way off piste here, but could you have the engine Terracleaned? Would that help at all?

[TheRenegade]

To be honest I don't really know. Looking at the assembly from above, it could be possible to try and get to it from the wheel arch liner. I guess there is only one way of finding out right? I seriously think my EGR needs replacing as its causing all sorts of issues.

[H8rxn.r]

Hey mate, did you manage to get to the EGR Cooler? I’m on the same boat

[necstandards]

Looked at the parts catalogue as it shows where it goes on...this is what I found

36554

Where would i find the parts catalogue?

[TheRenegade]

Where would i find the parts catalogue?

Original catalogs of auto parts. (https://7zap.com/en/catalog/cars/Audi/brand/3/0/Audi%20A6)

[liam walsh]

I'm in the same EGR cooler P2002 struggle. Did you manage you find a how to guide? That cooler is buried behind the DPF and under the turbo.

[necstandards]

I couldn't manage to change it, so gave it to a local mechanic that specializes in german cars here in Limerick. He managed to get a second hand throttle body & told me he cleaned the EGR valve located beside the throttle body (~€300). Gave it back but there was still something wrong - no low end power. Eventually after a week, more lights came on.... finally replaced the EGR valve and its running all fine again (~€500). Hope this helps!

[liam walsh]

Thanks , I'm in limerick too funnily enough.

[TheRenegade]

You guys are lucky...at least someone is willing to do it. There are several garages where I live. There aren't that many VAG specialist garages, the ones that are seem to charge almost dealer-like prices. I saw a video on the internet a few weeks ago where the guy took the DPF off to get to the EGR. It's no tutorial but it gives you an idea of what you have to do. He took the whole front end off! If I had a week off work maybe I could have a shot at it but it's a big job regardless. One guy told me that he has to take the subframe off to get to it from underneath :confused:. Then when I told him to go ahead and do it, he said he didn't have the "manpower" to do it as it needed a second pair of hands.

However, there doesn't seem to be any issues with mine at the moment. The DPF light comes on every other week though. I've been told that it's probably at end of life seeing as it's been on the car for 165k miles. After a short blast on the motorway at 3k rpm, it soon goes.

[liam walsh]

I removed mine today and letting it soak tonight. I'll refit it tomorrow. 3 hours to get it out. No need for a ramp you can do everything from the top once you remove the bulkhead just behind the engine. Alot of pipes and brackets to remove and a few tricky bolts but doable.
I removed the DPF while I was at it and that's gone for a full clean as VCDS said it was 3/4 of the way to max ash limit . Cars on 136k miles

[necstandards]

I removed mine today and letting it soak tonight. I'll refit it tomorrow. 3 hours to get it out. No need for a ramp you can do everything from the top once you remove the bulkhead just behind the engine. Alot of pipes and brackets to remove and a few tricky bolts but doable.
I removed the DPF while I was at it and that's gone for a full clean as VCDS said it was 3/4 of the way to max ash limit . Cars on 136k miles

Well, how did you get on?

[liam walsh]

Well, how did you get on?

Refitted DPF plus EGR cooler and the car is running well now , no faults , no limp mode . Only cost was the DPF clean by DPF Center in Kildimo and coolant. Happy enough now hope it lasts.

[necstandards]

Fair play Kidd - happy motoring!

[Bmt123]

Did you have to remove the front end of the car off to get the DPF out

[liam walsh]

No not completely just remove the bumper and loosen the bolts in preparation for front end removal and wiring plugs . Slide front end forward a few inches and the dpf will come out from the top.

[Cam91H]

No not completely just remove the bumper and loosen the bolts in preparation for front end removal and wiring plugs . Slide front end forward a few inches and the dpf will come out from the top.

When you say undo the bulkhead what do you mean exactly? Did you take the driveshaft off?

[liam walsh]

You can remove the steel bulkhead panel just behind the engine it gives you all the space you need to work on the back of the engine . No I didnt take driveshafts off there is no need everything can be done from above except a few dpf bolts if you are taking out the dpf.

[Cam91H]

You can remove the steel bulkhead panel just behind the engine it gives you all the space you need to work on the back of the engine . No I didnt take driveshafts off there is no need everything can be done from above except a few dpf bolts if you are taking out the dpf.

Cool ok cheers, I've started taking mine off today but currently stuck on the bolts that join the dpf to the exhaust there just isn't any room to get anything on them

[liam walsh]

When you take off the bulkhead panel you can get through to the 3 bolts holding the dpf to the exhaust using a few long extensions. You can see all three bolts heads if you remove the airbox. The bolts are torx spline heads . To remove the bulkhead panel you have to disconnect the heater pipes as they go through the panel.

You do know on that engine the egr cooler is attached to the dpf also. You have to take out the egr cooler to get out the dpf.

[Cam91H]

When you take off the bulkhead panel you can get through to the 3 bolts holding the dpf to the exhaust using a few long extensions. You can see all three bolts heads if you remove the airbox. The bolts are torx spline heads . To remove the bulkhead panel you have to disconnect the heater pipes as they go through the panel.

You do know on that engine the egr cooler is attached to the dpf also. You have to take out the egr cooler to get out the dpf.

Thanks mate lol, did you re-use the gaskets?

Yes I know they are joined together pretty much.

[liam walsh]

I think the only gasket is the one for the egr cooler to the dpf/scr cat. I didnt reuse because I ended up fitting a new egr cooler in the end but I would have reused it if I was putting the old one back in.

What's wrong with your car?

[Cam91H]

Money light keeps coming on with code p2002, it hasn't gone in to limp mode yet but just annoying being on all the time so thought I would do it while I'm furloughed. It had only done 40k miles when it first come on

[liam walsh]

Save yourself a load of hassle and change the map sensor first. 10 minute job . About £80 from audi.

[Cam91H]

To late now its in a million bits, just a few more bolts. How much was a new egr cooler?

[liam walsh]

Egr cooler comes with LP egr valve main dealer only around £450

[danclyon]

Save yourself a load of hassle and change the map sensor first. 10 minute job . About £80 from audi.


Dealer had mine for lengthy diagnotics and concluded the EGR cooler was blocked so changed that - £1950......fault came back inside 200 miles. 3 weeks of diags later, it was indeed that sensor - whole bill £140 done. I'm going to suggest that the nearly £2k of repairs were probably not necessary in the first place, and the £80 sensor was probably all that was wrong. A mate with a same vintage ultra had the same problems as me (just before me) and the Indy I normally used concluded it was that without the expensive main-dealer kit using nothing but deductive logic and VCDS :)

So yes, change that sensor first - and ONLY use a genuine one!

D.

[Sambor11]

Hy guys. My car is in Audi garage since yesterday and I had phone today. They said that cooler clocked and also dpf filter! They said they will contact Audi because must be something wrong. They replaced EGR and cooler 2 years ago ( 30k miles done since) and something like this???!!!. What MAP sensor is for guys?

[liam walsh]

What's your symptoms and what fault codes are you getting?

[Sambor11]

Exactly the same like orion1210 in first post. Car was driving like normal. And management light on dashboard. They gave me 33% off £1320. So £882 for job.

[Sambor11]

Exactly the same like orion1210 in first post. Car was driving like normal. And management light on dashboard. They gave me 33% off £1320. So £882 for job.

[danclyon]

Hy guys. My car is in Audi garage since yesterday and I had phone today. They said that cooler clocked and also dpf filter! They said they will contact Audi because must be something wrong. They replaced EGR and cooler 2 years ago ( 30k miles done since) and something like this???!!!. What MAP sensor is for guys?


Manifold Air Pressure sensor - mine was on the blink and was causing the exact same symptoms as the EGR cooler that the dealer had changed <250 miles earlier. They also assured me that the DPF was fine at that time yet the problems just came straight back. After 2 weeks of diags it was MAP sensor.

Cheers,
Dan.

[liam walsh]

Part number 04L 145 049 AE tell em change that first .

[Sambor11]

But they called me today after they removed cooler and dpf and foud both clocked.

[liam walsh]

How do they know the Oil cooler and Dpf are clogged ? Did they remove them today?

[Sambor11]

Yes. They removed today. I asked them for pictures, so if I will get them will post.

[liam walsh]

If they are blocked the MAP sensor wont be the cause of it or a cure.

Have you any ADBLUE faults?

[Sambor11]

If they are blocked the MAP sensor wont be the cause of it or a cure.

Have you any ADBLUE faults?

No ADBLUE faults. On 01/10/2020 were two faults.

Faults Found:
11901 - Manifold Pressure / Boost Sensor (G31)
P0236 00 [032] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:

19226 - Particulate Trap Bank 1
P2002 00 [096] - Efficiency Below Threshold
Intermittent - Not Confirmed - Tested Since Memory

But now is just second one.

[liam walsh]

It will be interesting to see the Egr cooler , SCR cat and DPF pictures.

How many miles on your car and how many miles since Egr cooler was replaced ?
What's you driving profile, short journeys / motorways?

[Sambor11]

It will be interesting to see the Egr cooler , SCR cat and DPF pictures.

How many miles on your car and how many miles since Egr cooler was replaced ?
What's you driving profile, short journeys / motorways?

85k miles on the clock, 32k miles since egr and egr cooler replaced. Driving everyday to work 27 miles one way. Trying keep 1600-1800 revs. When dpf burning out keep goi g until finished.

[Sambor11]

Car will be ready for tomorrow and I will update.

Pictures of cooler. Maybe problem is with Addblue?
375263752737528

[liam walsh]

No Adblu wouldnt cause that. What did Audi say was wrong with your car?

[Whippy53]

Adblue doesn't get anywhere near it.

[Sambor11]

No Adblu wouldnt cause that. What did Audi say was wrong with your car?
They don't know why this happened. Told me contact Audi UK. I will do but I think is wast of time. Maybe write to Audi Germany. Anyone can suggest to whom contact in Germany? A lot of people have this problem. Not only in UK.

[Whippy53]

Go to Audi UK first, write a clear, concise, well reasoned letter and send it registered post. Don't rant, don't threaten just lay the problem out and ask for a response within a reasonable time frame. Have a talk to citizens advice as well and document everything. If you get no response then elevate it up the line. Good luck.

[Sambor11]

Go to Audi UK first, write a clear, concise, well reasoned letter and send it registered post. Don't rant, don't threaten just lay the problem out and ask for a response within a reasonable time frame. Have a talk to citizens advice as well and document everything. If you get no response then elevate it up the line. Good luck.
Thanks for advice!

[liam walsh]

They don't know why this happened. Told me contact Audi UK. I will do but I think is wast of time. Maybe write to Audi Germany. Anyone can suggest to whom contact in Germany? A lot of people have this problem. Not only in UK.

What was the bill? DPF and Egr cooler plus labour you must be close to 3k .
Call this number 0800 699 888 and explain your case. Go from there. They're usual get out clause for this is your driving profile is not compatible with a modern DPF equipped diesel.
For comparison my car had 136k miles on it when I took out the cooler and dpf ( because audi tech notice says inspect EGR cooler first for P2002 faults) . The cooler was only slightly dirty , I changed mine because I didnt want to take it out again . My DPF was clear but reading close to 75% max ash so I got it cleaned while I had it all apart.
In the end my problem was the MAP sensor .

[Sambor11]

What was the bill? DPF and Egr cooler plus labour you must be close to 3k .
Call this number 0800 699 888 and explain your case. Go from there. They're usual get out clause for this is your driving profile is not compatible with a modern DPF equipped diesel.
For comparison my car had 136k miles on it when I took out the cooler and dpf ( because audi tech notice says inspect EGR cooler first for P2002 faults) . The cooler was only slightly dirty , I changed mine because I didnt want to take it out again . My DPF was clear but reading close to 75% max ash so I got it cleaned while I had it all apart.
In the end my problem was the MAP sensor .
Payed £882 ( they discounted me 33%)just for cooler. DPF was ok. Car is running now smooth. Did you have fault with MAP sensor, or you just replaced it?

[liam walsh]

Replaced sensor due car going into limp mode every now and then.

[Sambor11]

Replaced sensor due car going into limp mode every now and then.
Replace even no faults?
I can't find 04L 145 049 AE. Without AE there are but no with AE.

[liam walsh]

A mechanic with alot of experience on this particular generation of VW engine told me that if you have intermittent limp mode and a P2002 fault the first , easiest and cheapest attempt at a fix is replace the map sensor. After that go and look at EGR cooler and DPF.

[liam walsh]

Replace even no faults?
I can't find 04L 145 049 AE. Without AE there are but no with AE.

AE would be the revision status of the part. Ask the parts dept at your AUDI dealership. I replaced that exact part number during the summer.

[Sambor11]

Just pop up info on my dashboard today 'coolant low level'. Need to call Audi garage. Never had this before. Start leaking after they replaced egr valve cooler.

[liam walsh]

Just pop up info on my dashboard today 'coolant low level'. Need to call Audi garage. Never had this before. Start leaking after they replaced egr valve cooler.

Some very tricky limited access water pipe clamps down in that area.

[Sambor11]

Some very tricky limited access water pipe clamps down in that area.

Coolant today went below min again. I top up yesterday and can smell dump when I opened bonnet. And now the best part! Came back home today and plug vcds. And what?

2 Faults Found:
20169 - Exhaust Pressure Sensor 1 (G450)
P0471 00 [096] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:


9764 - Exhaust Pressure Sensor 1 (G450)
P0470 00 [032] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory

This faults didn't appear before but now exist! Like you said before this sensor was faulty, but why didn't show before? I will call Audi tomorrow! They probably didn't check faults after they replaced cooler.

[liam walsh]

Coolant today went below min again. I top up yesterday and can smell dump when I opened bonnet. And now the best part! Came back home today and plug vcds. And what?

2 Faults Found:
20169 - Exhaust Pressure Sensor 1 (G450)
P0471 00 [096] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:


9764 - Exhaust Pressure Sensor 1 (G450)
P0470 00 [032] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory

This faults didn't appear before but now exist! Like you said before this sensor was faulty, but why didn't show before? I will call Audi tomorrow! They probably didn't check faults after they replaced cooler.

I'm not 100% sure because it's a while since I looked at this stuff but ts possible that the G450 is the differential pressure sensor for the dpf and not the MAP sensor I mentioned earlier in the thread. The diff press sensor is an important one for DPF regens so would need looking at ASAP if it is. Is your oil level increasing do you know or have you checked?

[liam walsh]

Might be time to consider trading the car in for another while you have no lights on the dash. Early A4 B8.5 adblue cars are not the most reliable as they age. Only I can do 90% of the jobs myself I'd have got rid of mine at this stage. Only today it threw up an engine light due to a dodgy glowplug or wiring.

[Sambor11]

I'm not 100% sure because it's a while since I looked at this stuff but ts possible that the G450 is the differential pressure sensor for the dpf and not the MAP sensor I mentioned earlier in the thread. The diff press sensor is an important one for DPF regens so would need looking at ASAP if it is. Is your oil level increasing do you know or have you checked?
Engine oil is normal

[liam walsh]

Engine oil is normal

Keep an eye on it . If the car attempts dpf regen too often diesel can get into the oil.

[Sambor11]

Keep an eye on it . If the car attempts dpf regen too often diesel can get into the oil.
Regen is normal as well. Usually after 300 miles. Call them today and see.

[Gazwould]

Jesus what a pain this emissions equipment is , I'd get Frank to sort it out .

[liam walsh]

Going by past experiences of people that work regularly in dpf deletes / adblu deletes this particular generation of VW group engine do not take wheel to dpf / egr cooler deletes . Within a short space of time after delete the engines end up with bigger issues.
The Adblu you can delete as long as you dont have the adblu system fault countdown to no restart on the dash but will you make it through mot after I dont know.

[Sambor11]

Going by past experiences of people that work regularly in dpf deletes / adblu deletes this particular generation of VW group engine do not take wheel to dpf / egr cooler deletes . Within a short space of time after delete the engines end up with bigger issues.
The Adblu you can delete as long as you dont have the adblu system fault countdown to no restart on the dash but will you make it through mot after I dont know.
Should I replace this G450 sensor? Is just one or two?

[liam walsh]

Get the dealership to diagnose it . You've had a lot of work done in the area it could be a cracked vacuum hose, bad sensor , loose plug, damaged wire. Tell them you didnt have the problem before they worked on it and now you have . You know this because you did your vcds scans before and after.

[Sambor11]

Get the dealership to diagnose it . You've had a lot of work done in the area it could be a cracked vacuum hose, bad sensor , loose plug, damaged wire. Tell them you didnt have the problem before they worked on it and now you have . You know this because you did your vcds scans before and after.
Yiu are right. Will call them.

[Sambor11]

Booked on Tuesday.

[liam walsh]

Booked on Tuesday.

What sid Mr Audi say?

[Sambor11]

What sid Mr Audi say?
It was damaged hose from ccoolant container. I asked them as well one more time to check for fault codes specially for sensor G450. Should get call today later on.

[liam walsh]

It was damaged hose from ccoolant container. I asked them as well one more time to check for fault codes specially for sensor G450. Should get call today later on.

The plastic couplings on that line crack easily . That line is about £50 if I remember correctly.
Keep us updated with their findings on the G450 issue.

[Sambor11]

The plastic couplings on that line crack easily . That line is about £50 if I remember correctly.
Keep us updated with their findings on the G450 issue.
I just spoke with mechanic. He said that last time probably disconnected connector abd didn't clear fault codes. They clear now. When I'll get my car back will check one more time.

[liam walsh]

You can see the date time and mileage when the fault logged if you have a record kept of the vcds fault . Then you can see if it was while in the dealers or afterward.

[Sambor11]

You can see the date time and mileage when the fault logged if you have a record kept of the vcds fault . Then you can see if it was while in the dealers or afterward.

It was in Audi garage. They replaced leaking coolant hose £18, cleared fault codes and now everything is fine. But. I bought from Audi boost pressure sensor on Thursday and today I want to replace but when I opened box I was little confused. In my car is sensor 03L906051B with two pipes and sensor which I got is 04L906051K with one pipe ( picture below). Somebody can tell me what's going on guys????
37584

[Vash]

You can see the date time and mileage when the fault logged if you have a record kept of the vcds fault . Then you can see if it was while in the dealers or afterward.

How do you actually test the MAP sensor before you buy one, Liam ? I have Autel MK808 and VCDS, but don't think the sensor will be short to ground. Am I looking for some deviation from normal values ? And if so, what are the normal operational values ?

Thank you

[nordic_b]

I don't think you can test MAP sensor in an easy way, unless it has completely failed or deviates from atmospheric pressure.
I'm going through the same vows now, have both the P2002 and AdBlue with limited mileage faults, but garage is taking a look at it as it is still under warranty. Quite upsetting tbh - thought I've got a good untouched example.

[danclyon]

They don't know why this happened. Told me contact Audi UK. I will do but I think is wast of time. Maybe write to Audi Germany. Anyone can suggest to whom contact in Germany? A lot of people have this problem. Not only in UK.

Meant to share this - I got a copy of the TPI for my fault from the dealer (as it was under warranty)......

38726
38727
38728
38729
38730

"Special Driving Profile" = cop out. My driving profile was "enthusiastic" (sometimes very) - it could well have been the previous owner (from new) but he got through a set of brakes and 3 sets of tyres in 50k miles, so I'm going to guess he was even more "enthusiastic" with me!

Hope that's useful for someone.

D.

[nordic_b]

I'll be doing the EGR cooler this or next week and post some pictures of what I find, just waiting for seals to arrive. Not going to replace it, because by looking at it, it should be possible to clean - oven cleaner does wonders for this type of stuff. Same CNHA engine and P2002 code.

Does anyone know if ECU firmware version help with this build up or not really? Mine is still on original 0654, while latest is 9567 for ECU 04L906021FR.

[Crasher]

The people we use to clean DPF's, DPF Clean Team, can't shift the urea crystals with their gear.

[nordic_b]

That's a good point... Something to think about. Thanks

I think some of the stuff that can potentially dissolve urea crystals can also attack ceramics, therefore cannot be used on DPF. I'll give it a try and see if anything works.

[danclyon]

The people we use to clean DPF's, DPF Clean Team, can't shift the urea crystals with their gear.

Crasher, you literally mean "they cannot take the p*ss" ?

:biglaugh:

[Crasher]

Yes, they are unable to extract the urine...

[nordic_b]

Guys, I can tell you, this is pig of a job. Overengineered cr@p. Give it to someone to do it if you want to retain your sanity :aargh4:

[Crasher]

That is why my mechanics are bonkers then...

[nordic_b]

Hey guys, as promised, few pictures.

I'm not totally convinced it was badly blocked, but I let you and the car judge. Need to drive more for this fault to reappear.
38745 38746 38748 38747

After. You can see dimples (by design) inside the tubes, that probably contribute to blockage.
3 bottom tubes are straight through, perhaps for oil passing through easier?
I rinses it in the oven degreaser concentrate in the water (nasty stuff, wear gloves if you use it) for about 10 minutes. It attacks lots of stuff, including metals, so don't leave it overnight :) Urea crystals and everything have dissolved.
38749

I opened up the egr valve to see how plastic gears look, they looked ok, but greased them with non-petroleum grease.
38750

Cleaned everything and assembled back.
It ruined my hands, they look like I got attacked by 10 hungry cats.
This freak of engineering looks like a nuclear reactor.
38752


If anyone is going to attempt this work, 15-20 hours, as mentioned, is probably about what it takes if to do it properly, e.g. respecting torque specs, using copper grease, etc.
You'll need to drain coolant or, like I did, drained liter or 2 from the cooler itself.
You may also need:
- Inspection mirror
- Magnetic pickup - you'll drop endless stuff
- Endoscope helps too, some places/bolts are not visible from any angle - who designed this?

Tools that I really needed and did not have:
- dedicated hose clip pliers - absolutely essential
- various lengths torx bits

Parts I had to remove/detach:
- Air filter assembly / front rad cover
- Top brace
- Bottom cross member
- Disconnect downpipe from the gearbox mount
- DPF assembly detached from the exhaust and the turbo, did not need to remove

This allows to wiggle things out in some magic manner, rubic's cube springs to mind.

38751

[Crasher]

Some of those pics trigger my trypophobia...

[nordic_b]

Sorry. I do get a bit of that too!

[Crasher]

I couldn't remember the correct spelling so Googled it and the result nearly made me fall off my chair, it is a bizarre phobia and I have no idea what started it.

[danclyon]

Hey guys, as promised, few pictures.

I'm not totally convinced it was badly blocked, but I let you and the car judge. Need to drive more for this fault to reappear.
38745 38746 38748 38747

After. You can see dimples (by design) inside the tubes, that probably contribute to blockage.
3 bottom tubes are straight through, perhaps for oil passing through easier?
I rinses it in the oven degreaser concentrate in the water (nasty stuff, wear gloves if you use it) for about 10 minutes. It attacks lots of stuff, including metals, so don't leave it overnight :) Urea crystals and everything have dissolved.
38749

I opened up the egr valve to see how plastic gears look, they looked ok, but greased them with non-petroleum grease.
38750

Cleaned everything and assembled back.
It ruined my hands, they look like I got attacked by 10 hungry cats.
This freak of engineering looks like a nuclear reactor.
38752


If anyone is going to attempt this work, 15-20 hours, as mentioned, is probably about what it takes if to do it properly, e.g. respecting torque specs, using copper grease, etc.
You'll need to drain coolant or, like I did, drained liter or 2 from the cooler itself.
You may also need:
- Inspection mirror
- Magnetic pickup - you'll drop endless stuff
- Endoscope helps too, some places/bolts are not visible from any angle - who designed this?

Tools that I really needed and did not have:
- dedicated hose clip pliers - absolutely essential
- various lengths torx bits

Parts I had to remove/detach:
- Air filter assembly / front rad cover
- Top brace
- Bottom cross member
- Disconnect downpipe from the gearbox mount
- DPF assembly detached from the exhaust and the turbo, did not need to remove

This allows to wiggle things out in some magic manner, rubic's cube springs to mind.

38751

Looks about as bad as the pictures in the Audi TSB I shared.......mine was about the same when I received the photos from Audi post dismantling.....

[nordic_b]

I wonder if the blockage is more due to the crystallization or the soot. The soot, by feel, was very light, fluff like, urea deposits were fairly hard. There are few adblue additives (additives on additives the world we live in) that claim they prevent forming hard urea deposits, e.g. Forte, Wynns, Total, but they seem to be mainly designed for trucks, business, not consumer. I've just had adblue injector cleaned and only few hundreds km from then I already see white stuff forming on the nozzle, but it's more powder like rather than hard depositing.

[Crasher]

It is the urea deposits, they set like cement; apparently it is a huge pain with big commercial Diesels.

[Whippy53]

It is the urea deposits, they set like cement; apparently it is a huge pain with big commercial Diesels.

And my keks, according to the missus.

[Crasher]

And my keks, according to the missus.

eeewww yuk :eek:

[nordic_b]

So after about 400km after the egr cooler cleaning the fault is not returning, thanks to this post!
I watched a couple of youtube videos on this job and it brings memories of pain and some people take it way further than I had to - what a horrible design and new cars in general.

[kkgg]

Hello everyone!
P2002 on mine 2015 CNHA A6 brought me here.
This is my first post here so let me introduce myself 😊. I'm Christopher, live in Poland and I've been using my Audi daily since 2017 to drive myself to work about 60 miles back and forth couple times a week with a highway (60-80mph constant speeds)... No major issues with the car so far (150k miles odo) but it started showing this P2002 error some time ago. No other symptoms so after doing some research I'm pretty sure it's all about this damn cooler.
I already bought some excellent condition used one (20k miles) and it was really a bargain (20£) but the labour at dealers gave me a headache (1200£, thought I'm pretty sure they quoted me that amount only to get rid of me)... Anyway - I decided to do it myself. I'm pretty sure I have all necessary stuff (jack and stands, endoscopic camera, spline torx bits, hose clamp tool etc) and skills (two hands LOL) to manage it but still I have some questions (especially to nordic_b as he's done that by himself).
Is it necessary to undo DPF filter while I'm not intending to clean the thing?
Exhaust pipe... Is it necessary to take it away or can I just undo it from DPF filter and move away a little?
The cooler itself if fastened to DPF with couple of bolts and with a bolt and bracket from the back. Is it possible to reach the lower bolt holding this bracket to the engine from the top?
Any other tips would be highly appreciated. Thanks!

[Crasher]

I did the first service on a 10k mile 2022 A4 yesterday, I was horrified at the complexity of the exhaust after treatment system... insane. DTNA code engine "EU6 AP" standard, pre cat with AdBlue injector, DPF and then a second cat with AdBlue injector so if the pre cat injector fails and blocks all three units that is £7000 in major parts alone, effing madness!

[Sergiu_zee]

Hi! I had the egr cooler changed a week ago at a local service i trust. 250euro labour and 325 euro the part ( new original).
It s a 2 day job. Not extremly complex but time consuming. The dpf wasn removed but you need to remove the front exhaust. You have to remove almost everything under the wipers. Be careful at the lower bolts down the exhaust pipe. Mine were rusted and broke. Besides the cooler you need the gasket between the egrvalve and the cooler. I reused the gasket that s between the dpf and the cooler.( i would have replaced with a new one but i din t want to wait another day). Clean the egr valve while you re at it.mine was preety clean. Be careful at the couplings they tend to brake. Post if u need further details.gl

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[nordic_b]

Hi there.

It looks like there are numerous ways people attack this job, because procedure is not really defined and Audi documentation limits it to removing EGR cooler as if it was on the market shelf.
Surely we all want to tackle this job with as little disassembly as possible.

To answer Christopher's question. I have undone DPF filter with an intention to remove it from the engine bay, but it is impossible without front disassembly it seems. I could only wiggle it a little in the available space. I think you can try going without undoing the DPF and if you are not getting anywhere, probably have to undo it at least. I did not remove any of the downpipes, only disconnected them from the DPF (and gearbox mount). Reason I needed access from beneath is because I hadn't enough leverage to undo DPF nuts from above. Please mind, that those 3 nuts are copper and at your mileage they can be corroded, round and what not. Replace them anyway, including the gasket.
I did not touch the firewall at all, only removed top plastics and the brace.
Few items to note is:
- if you undo the DPF assembly, the top bolt near Nox sensors actually screws onto a height adjustment screw, so note its position.
- have something soft on top of the engine to protect all those gentle plastic stuff, I had to lie on the engine with all my weight.
- how wiring loom near the firewall goes. In the end I found I could route it in numerous ways and none seemed right.
- DPF pressure metal pipe that goes into pressure sensor, if you remove it, don't forget to put it back before you put anything on top of the EGR cooler, otherwise it may be impossible to route it through later.
- Plastic breather pipe, be gentle with it, they tend to become brittle over time/miles.

It's a pretty cr@ppy job, so only can wish you luck and a lot a lot of patience. Check torque settings as well as these are scattered all over the documentation.

The other thing I have noticed is that after cooler cleaning, my consumption went up a little. Or maybe it is just winter and cool air.

[kkgg]

Thanks guys!
I just got a little more overwhelmed with all what's been written 😅.
I'll do it! I know I can! Just need to find some blank space in my calendar.
I'd appreciate those torque specs if you still have them somewhere! Thanks!
BTW - those copper bolts.. do you mean those holding DPF to the engine or those at the cooler/exhaust pipe? Or maybe all of them? Do I need any kind of copper grease for those?

[Crasher]

Nuts man, nuts! Copper ones ;) You MUST replace EVERY fastener you remove… without exception, almost! They don’t need lube in most cases but those in high heat apps must have “hot bolt paste” applied G 052 112 A3 which is £78.08 for a 170 gram tube.

[nordic_b]

As Crasher says, replace bolts/nuts, but in real life I can rarely see anyone doing it. I do replace some in critical areas but do feel people look odd at me when I buy bolts for few quid each. Bolts are like ink cartridges, probably make most of the money for Audi.

I use copper grease a lot during assembly. Usually on hot mating surfaces and bolts and nuts that can be exposed to heat or moisture. Note however, that grease can effect torque reading, usually resulting in overtightening stuff even with torque wrench.

Those 3 copper nuts are attaching DPF to the downpipe, if you are going to undo it. They are pretty soft, people split them with something sharp if they are beyond gripping with anything.

[kkgg]

You mean... Like hammering those with some sharp tool, splitting in halves and then just taking them away? :O... And what about those bolts then? Aren't they ruined with that kind of treatment? Are those also to be replaced? Couldn't find any specific P/N for those. Sorry for those newbies questions but it's the first time I'm going to touch anything at the exhaust 😎

[Crasher]

As Crasher says, replace bolts/nuts, but in real life I can rarely see anyone doing it.

We do, religiously. We have an alcove in the stores with three sides floor to ceiling with linbins of fasteners, thousands of pounds of them. This is an old pic, they are right to the floor now many bins double of triple part numbered.

https://hosting.photobucket.com/albums/dd20/Crasher1964/.highres/69d2d6d8-cd46-40cb-8690-3689418d3ac8_zpsezhrxkhn.jpg

[kkgg]

Hi all!
I'm back just to let you know that I managed to replace the faulty cooler. I've done that without removing exhaust pipe, almost all job done from top of the engine laying on it. A bit tricky but doable when you undo and move the lower cooling pipe that runs behind the engine on top of the transmission out of the way.
If you do that there is just enough room to unscrew all of the bolts holding the cooler.
Yeah, that's really awful job. Took me about 15 hours though I think I could do it in less than 10h next time.
Thank you guys for your clues!

BTW I have a question about DPF filter condition.
I played a little with OBD11 and found that "oil ash mass" seems to be really close to "limit" value (76g/80g)... My car is running fine, most of my driving on the motorways. Odometer is about 266.000 kilometers (about 165.000mi). DPF regen starts more or less every 600-700km (about 400mi) and it's really uncommon for me to interrupt this process.
Does the oil ash mass value mean that I have to replace my filter anytime soon?

https://images92.fotosik.pl/669/6f0ce29131c651e5med.jpg (https://images92.fotosik.pl/669/6f0ce29131c651e5.jpg)

Would you please help me to understand that? Thanks!

[Crasher]

We have just been through a living nightmare with a 2017 A6 Ultra, it only left a few hours ago. It came in two weeks ago saying 500 till no start. We endescscoped the starter cat through the injector port, full of Urea cement. It took two full days including lifting the engine to one side just to get the system out of there, it is HUGE and that's only the DPF never mind the starter cat on top, EGR cooler and cat under the car.

https://live.staticflickr.com/65535/52972418800_282e3516ac_o.jpg (https://flic.kr/p/2oGZuzw)

The EGR cooler was solid so I put it in the ultrasonic tank with some aggressive Alkaline and after a day at 80 degrees C it was clear, arghh that triggers me trypophobia

https://live.staticflickr.com/65535/52972382655_cd4a43c4be_o.jpg (https://flic.kr/p/2oGZiQk)

Everything was clogged

https://live.staticflickr.com/65535/52972143724_85551e4f0e_o.jpg (https://flic.kr/p/2oGY5NQ)

The starter cat, DPF and SCR cat were another case! We sent these to DPF Clean Team and it took two days in their dip and furnace/repeat to get the flow to spec. It took my tech two days to build it all back in and then he ****** off on holiday so muggines here had to finish it which took another full day. I did a regen, filled up the reductant tank etc and all good, no codes, no warning off she goes, £3500 please Mr customer.

Next day, "my dash says 450 miles until restart", like ***! No codes in the ECU or reductant tank ECU, 100% reducant, nothing. I then spent hours going through tests, ran the injector into a jug and great flow (new injector BTW, £350) but the warning would not clear., ran dosing tests and the stench that stuff makes when hot, Yak! So it was flowing.

I started trawling through the measuring blocks in the engine ECU (the reducant ECU tells you sod all) and stumbled across reductant pump pressure -500mBar... Now I have seen measuring blocks be false friends before so I used ODIS and it said it must be between 4500 and 5500 mBar, not MINUS 500mBar. Obviously this was wrong so I had a faulty pump out of a full replacement secondary tank (they have two!) I did in an A4 a few weeks back (£2000!!) and the pump is identical, plugged it in out of the tank, reading attmo basically. So I ordered a new genuine pump (£700) and did the same test, attmo. To get the pump out of the A4 tank means removing a big traditional plastic nut like on a plastic fuel tank but upside down... The A6 pump is held in with a metal ring like cars from the 60's and requires tool T40268

https://www.chain-auto-tools.com/cache/com_z2/CM_88eafe07e80839b0eded3f66ed7475ea_AMR1328L-1-INST.jpg

Hello TPS, how much is T40268... £60 Crasher (even they call me that now), great, tomorrow ASAP please, nope... back order... FFS! Get me a new tank then, they are £400 but come with a redesign using the plastic ring... nope, back order... God give me strength!

So I then spent the next three hours making one out of bar stock and by God those locking rings are tight.

I then drained the FULL tank of AdBlue I put in last week (ELSA says not to re-use) which is a disgusting job.

Fought to release the ring and bang off it came followed by approx 5 litre of AdBlue that had not drained which sprayed ina 360n degre waterfall allo ver me, hair, clothes, feet... I was one big AdBlue rag.

Pump fitted, bled, bust a gut reinstalling the ring, ODIS tests etc, 5000mBar showing no codes, still saying 450... like what!

I then trawled through the TPI's in erWin and found a notification about THE exact problem and an engine ECU update action code, brill! Checked the numbers, already been done... Oh God why did I choose this trade?

Then I found a little note in ODIS special functions about an unclearble 450 mile warning in the dash (without supporting codes in the engine ECU) after reductant pump and/or control ECU replacement and it said click continue and ping, warning gone and not a word of explanation. Without ODIS and GEKo this job would be impossible.

My conclusion is the whole thing was caused by the pump going crazy injecting reductant because of a poxy sensor in the pump that does not come up as a code when faulty, crap software... now where have I noticed that before with VAG software?

[kkgg]

Sounds like lots of fun B⁠-⁠)
When I get my warning I'll just put my car inside a ship container and send it straight to you. You're experienced professional :)

[Crasher]

The furthest ones that have been sent is from Majorca and East Norway.

[Amigo]

Commiserations! I got off lightly last summer with a bill of £1,400 for DPF cremoving/cleaning/fitting then.

[MarkDa]

Hi Liam
Is getting the footwell access panel off-out fairly straightforward?
Regards
Mark

[Audid]

Any recommendations for garages in and around London/ Essex/ Kent area please? Need to get my egr cooler issue resolved. Thanks

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