2016 3.0D A6 Allroad (218ps) - Coolant Leak & MIL..

[Chrisssyg]

Morning all,

My first post on here despite lurking and reading for a little while to learn a bit about the C7/general issues.. I bought a 2016 A6 Allroad (218PS) in Feb and have had no issues with it since then - until now.. (It was only a matter of time, it's done 86k miles..). The day I bought the car and drove home, I notice the coolant was a little low so I bought some and topped it up to max and thought nothing more of it - since that point, I've done 2500 miles in it and thought I'd give it a check again. It was on the minimum line, and I think I can see the likely area (given a small drop of red water on the undertray) - is this likely to be a water pump issue given the location which is looking into the engine bay, from the front of the car on the right hand side of the floor (picture attached)? Or something else that the 3.0D is known for? I've got a warranty on the car but as I bought it from a dealer, the onus is really on him to fix it as the fault was there on purchase.

The second issue is an amber MIL light which came up on the dash a couple of days ago (not driven since). I've plugged a very simplistic wifi OBD fault code reader onto the car and had code P20EE & 17277 come up which I believe relate to a NOx sensor below threshold, but I can't get much further than that to work out which one with my device. I probably should just take this one to get sorted under warranty (but I know how these places like to squirm their way out of paying for things like this) so I'm trying to do a bit more homework. Do the codes I've mentioned relate to a specific NOx sensor or is it too difficult to tell that from those codes and more investigation is required? 

I'd quite like to get VCDS at home as I'm a fairly competent home/amateur mechanic and I suspect it won't be the last time I need to diagnose something - what's the best way of doing so? I've seen lots of cables and CD's on eBay claiming to be the real deal - should I trust this or is there a better/more sensible option to getting access to some more advanced diagnostics for it?

As far as the car goes, I absolutely love it. It does everything I wanted it to and I'm even growing fond of the "brown" paintwork.. Picture of the car attached on a recent trip into Wales because why not!

Any thoughts / help you can give would be greatly appreciated.

Thank you!

Chris 

 

[a6blacked007]

Get it back for warranty work let them sort it sooner the better buddy.

 

Always leave email or messages so youve got dates and times you made them aware .

[Morgan79]

A good friend of mine had a RS6 with the same issue, he would top up the level and it would leak a little 'from somwhere' so he took it back to audi after becoming obsessed with it... Apparently it was releaseing additional coolant to bring back to nominal level, so he stopped topping up and remained steady around the min level. 

[Chrisssyg]

Thanks for the replies. 

13 hours ago, a6blacked007 said:

Get it back for warranty work let them sort it sooner the better buddy.

Always leave email or messages so youve got dates and times you made them aware .

Absolutely, I think the leak was there when I bought the car so a dealer has an obligation to rectify that fault via warranty or otherwise. I've got plenty of texts to/from him covering that so should all be fine - good point though! 

Agree - but like with all things, the warranty is pretty incomprehensive.. It includes £50 diagnosis (cost to diagnose is circa £70-80), then they'll cover £50 an hour labour, but labour here is £80-85.. So if I can do a bit of diagnosis here, I'll end up saving myself some money as I'll have to shell out for the diagnosis cost over £50, along with any labour costs over £50 too..

4 hours ago, Morgan79 said:

A good friend of mine had a RS6 with the same issue, he would top up the level and it would leak a little 'from somwhere' so he took it back to audi after becoming obsessed with it... Apparently it was releaseing additional coolant to bring back to nominal level, so he stopped topping up and remained steady around the min level. 

That's interesting.. I'll keep that in mind. I'd be a little surprised to see coolant weeping from the area in the picture if it was just settling to a nominal level though, I'd assume it'd come out of the expansion tank overflow rather than from somewhere that looks suspiciously like where water pump is located. Is the water pump in that area? I can't seem to find any diagrams that I'm sure match my engine..

Any views on how best to get VCDS at home? Is an eBay copy safe?

Edited May 23, 2023 by Chrisssyg

[Morgan79]

16 hours ago, Chrisssyg said:

Thanks for the replies. 

Absolutely, I think the leak was there when I bought the car so a dealer has an obligation to rectify that fault via warranty or otherwise. I've got plenty of texts to/from him covering that so should all be fine - good point though! 

Agree - but like with all things, the warranty is pretty incomprehensive.. It includes £50 diagnosis (cost to diagnose is circa £70-80), then they'll cover £50 an hour labour, but labour here is £80-85.. So if I can do a bit of diagnosis here, I'll end up saving myself some money as I'll have to shell out for the diagnosis cost over £50, along with any labour costs over £50 too..

That's interesting.. I'll keep that in mind. I'd be a little surprised to see coolant weeping from the area in the picture if it was just settling to a nominal level though, I'd assume it'd come out of the expansion tank overflow rather than from somewhere that looks suspiciously like where water pump is located. Is the water pump in that area? I can't seem to find any diagrams that I'm sure match my engine..

Any views on how best to get VCDS at home? Is an ebay copy safe?

I only had my allroad a litte over a week ago, bit the bullet and purchased a genuine unit from https://www.gendan.co.uk uk supplier Ross-tech and only a hour or so away from me.

I already had a carista dongle I picked up years ago for my other vehicles which I used to check the car before purchasing...

It has error checking functionality and some modification options but not nearly as much as the VAGCOM has, but only around £35 on Amazon, if your interested in this see https://caristaapp.com/en/supported-cars for what it can do on the A6.

I was after something that could complete towbar coding and know the value of having additional access to the systems after using a IID tool for years with my departed Discovery. 

[Tigger]

Hi Chris,

Coolant Leaks

Take the plastic engine cover off... Shine a torch down the 'V' of the engine and look for the reflective shine of wet metal and/or puddles down there... (V6 Engine, has two sets of 3 cylinders, and a lot of pipes and cables running down the V that runs front to back between the cylinder heads - for those that might not understand what i mean) Towards the back of the engine there is a valve called the "Cooling System Bypass Line Adapter" - a valve controlled by a Vacuum line that diverts water to/from the Exhaust Gas Recirculation system when required... That's what failed for me recently, and is a commonly known fault for these 3L V6 TDI Engines.

The good news is that the replacement valve should cost between £35 and £60 depending upon where you get it from.

The bad news is that they have to practically disassemble the EGR system and clear out all the cables/pipes in the V of the engine to get to it and replace it - so Labour to fit the !Removed! thing cost me £600.

The result is good though - coolant stays at whatever level is put in...

Fault Readers

As far as OBD Fault Code Readers - I have an 'OBDEleven' - Google will guide you to it if you're interested...

It reads codes, but also allows a fair amount of customisation... I've changed the wipe period of my rear wiper - once every 6 seconds was far too frequent - now it wipes every 20 seconds which is more than frequent enough. I've changed the functionality of the Start/Stop system so that it doesn't revert back to start/Stop being active every time I get in the car - now it remembers how I had it set between each time I use the car. And I've turned on the 'Scandinavian' DRL - where your front lights have the white LED's lit whenever you drive the car, mine has the front white running lights and the tail lights on at all times - basically the same as having the side lights on at all times, which is what I've always done in previous cars. I've also activated both opening AND closing the tailgate via the door button and the remote control. There's tons of other stuff you can do too, if you wish...

 

So yeah, just my thoughts on the matters...

Tigger

[Chrisssyg]

On 5/24/2023 at 3:25 AM, Morgan79 said:

I only had my allroad a litte over a week ago, bit the bullet and purchased a genuine unit from https://www.gendan.co.uk uk supplier Ross-tech and only a hour or so away from me.

I already had a carista dongle I picked up years ago for my other vehicles which I used to check the car before purchasing...

It has error checking functionality and some modification options but not nearly as much as the VAGCOM has, but only around £35 on Amazon, if your interested in this see https://caristaapp.com/en/supported-cars for what it can do on the A6.

I was after something that could complete towbar coding and know the value of having additional access to the systems after using a IID tool for years with my departed Discovery. 

Thank you - had seen those but wasn't sure I was ready to spend the £200, but that being said, it'll pay for itself quickly if I need to do some diagnostics and it's £80 a time at a garage.. My basic OBD tool might be enough to get me by for now.. Good advice, probably should just bite the bullet!

16 hours ago, Tigger said:

Hi Chris,

Coolant Leaks

Take the plastic engine cover off... Shine a torch down the 'V' of the engine and look for the reflective shine of wet metal and/or puddles down there... (V6 Engine, has two sets of 3 cylinders, and a lot of pipes and cables running down the V that runs front to back between the cylinder heads - for those that might not understand what i mean) Towards the back of the engine there is a valve called the "Cooling System Bypass Line Adapter" - a valve controlled by a Vacuum line that diverts water to/from the Exhaust Gas Recirculation system when required... That's what failed for me recently, and is a commonly known fault for these 3L V6 TDI Engines.

The good news is that the replacement valve should cost between £35 and £60 depending upon where you get it from.

The bad news is that they have to practically disassemble the EGR system and clear out all the cables/pipes in the V of the engine to get to it and replace it - so Labour to fit the !Removed! thing cost me £600.

The result is good though - coolant stays at whatever level is put in...

Fault Readers

As far as OBD Fault Code Readers - I have an 'OBDEleven' - Google will guide you to it if you're interested...

It reads codes, but also allows a fair amount of customisation... I've changed the wipe period of my rear wiper - once every 6 seconds was far too frequent - now it wipes every 20 seconds which is more than frequent enough. I've changed the functionality of the Start/Stop system so that it doesn't revert back to start/Stop being active every time I get in the car - now it remembers how I had it set between each time I use the car. And I've turned on the 'Scandinavian' DRL - where your front lights have the white LED's lit whenever you drive the car, mine has the front white running lights and the tail lights on at all times - basically the same as having the side lights on at all times, which is what I've always done in previous cars. I've also activated both opening AND closing the tailgate via the door button and the remote control. There's tons of other stuff you can do too, if you wish...

 

So yeah, just my thoughts on the matters...

Tigger

Thanks Tigger - yeah aware of the engine layout and had read about that valve leaking on this forum but had a poke around initially and couldn't see any wet areas. Your post made me go out again and have another look and sure enough, I can just see the bottom left part of the oil cooler with some coolant around it, so it'll definitely be a similar thing. On that other forum there seem to be a few other bits which could be leaking too, so I think I'll probably strip the engine at some point soon, buy a load of those bits and just replace them for peace of mind. I haven't worked out how it's dripping down the front of the engine yet but it's probably just the path it travels due to gravity rather than being a water pump leak too. Is the water pump located on the front right or front left of the engine do you know?

Again, useful stuff to know and a good alternative to the full VCDS/Vagcom but with most of the functionality.. The wiper timing change along with the tailgate close would be very useful features to have.. Will have a ponder! Thanks for taking the time to reply.

Chris 

[Chrisssyg]

Hi all, I'm back. I've had unsurprisingly, very little luck with the 3rd party warranty provider.

They're refusing to cover the amber MIL light - which due to a friendly local garage helped me diagnose the fault from two codes (P20EE00 - SCR NOx catalyst efficient below threshold bank 1, and P20EE SCR NOx catalyst efficiency below threshold bank 1 catalyst 1) from which they suspected the catalyst needs replacing. Calling Audi it seems the new catalyst is circa £1900, plus any new sensors I might need if the old ones can't be easily removed at an additional £800 or so.. So I tried asking the local Audi dealer for what the part numbers might be but they told me they weren't able to tell me. Apparently there's only one cat on this car rather than the expected two.

It's quite a steep bill and one I'm not really prepared to pay unless I absolutely have to. I guess my options are:

1. Pay the bill and get a local garage to fit parts from Audi

2. Find the part numbers (anyone able to help? Have looked and not found it easy to know 100% what is the right one on a 2016 218PS allroad), order online and fit myself (I'm relatively handy)

3. Buy a second hand cat and fit that - but I also need the part numbers for that

4. Buy a cat delete pipe and have the ECU coded to no longer need that input but I'd rather keep the car stock if I could - suspect this'll be the cheapest option..

 

Any thoughts / help would be greatly appreciated!

Don't get me started on the leak..

Thanks in advance,

Chris