Boxer 2.0 blueHDi 2018 - High Oil Consumption and code P0428

[JonnyBell]

Hi all. I'm new to the forum. Seem's like an amazing resource and I hope I can get some good advice. I hope you all can humour this long post... I thought it best to share everything i know...

My 2018 Boxer van has done only 47k miles (1 previous owner from whom I bought it at 37k miles).
I put it through a major service at 40k miles (I do not suspect any faults arose from this).

Main concern is high motor oil consumption. Been using on average 1.2L of oil per 1k miles.
Until recently, there has been NO performance issues or any symptoms related to this... But I fear this consumption may be increasing and causing some slow damage.
In the last 300 miles i have noticed a slight turbo whistle while revving from idle but only audible outside and the slightest bit of hesitation in acceleration occasionally in varying conditions... but this could be my over thinking and/or recent cold weather.

The following positives have been observed by myself and 3 seperate mechanics over the last 5k:

No visable oil leaks anywhere in the engine bay or below (including around turbo)
No smoke of any colour from exhaust
Not overheating or loosing coolant (tank sits at min when cold, max when hot)
No visible oil in coolant/coolant in oil (sniff test done at service)
Heater blows hot and cold as expected.
No excessive engine knocks or noises.
No excessive oil in boost pipe (residual only).
No performance issues while driving and plenty of power (until recent turbo concern)

It has been suggested that, if nothing else, this could be an issue with the PCV breather which is contained within the rocker cover. One mechanic claims he managed to pop the circular cover off to inspect the actual PCV diapragm, but could see no tears/wear.

My next step is now going to be a compression test of the cylinders to rule out piston/ring wear (this has been avoided so far due to there being no symptoms for ring wear and also due to the labour involved in accessing the glowplugs (which i believe to be not straigtforward on these engines?)


The next concern is the reoccuring P0428 code (Catalyst temperature sensor circuit high, bank 1 sensor 1) -

This code has been regularly appearing for the last 3k miles. Which my self and 2 mechanics have cleared about 10 times after suspecting a simple sensor failure and therefore seeing no risk of any damage.
I have been hesitant to simply swap out two 02 sensors (up/down stream of pre cat) as I now suspect oil consuption to be linked/causing this code.

Live data has been continually monitored since with my basic bluetooth code reader dongle and phone app.
When P0428 code is triggered, the stated cat temp is usually only at around 350°c (not the stated 900°c max trip value).
This might suggest infact a faulty sensor, but perhaps that sensor is getting damged by excessive oil entering the cat and causing genuine damage to it.

Access to these O2 sensors is very difficult to back probe and test voltages myself without use of a proper ramp/lift.

I do not suspect the DPF is blocked, but the cat may be slowly blocking and therefore hiding any smoke exiting the tailpipe?

Adblue injector was recently cleaned with only small amount of carbon needing wiped off and no crystalisation found.


The following is the limited data i have observed from my basic scan tool (all figures achieved at operating coolant temp of 80-97°c) :-

Catalyst temp bank 1 sensor 1:
idle 183°c
2000rpm (driving) 381°c
3000rpm (stationary) 200°c
(never seen cat temp go above 600°c in regular use while moitoring)

O2 Lambda bank 1 sensor 1:
idle 5.1
2000rpm (driving) 1.7
3000rpm (stationary) 5.7

DPF differential pressure (concerned these are strangely too low! opposite of blocked):
idle 1kpa
2000rpm (driving) 8kpa
3000rpm (stationary) 8kpa

Downtream NOx sensor (i believe only one in the van. after DPF. I'm concerned these values are too high):
ilde 139ppm
2000rpm (driving) 638ppm
3000rpm (stationary) 282ppm


It would of course be useful if i could see O2 sensor voltages and fuel trim data too, but i cant access these so will seek mechanics diagnistic soon. Also get hild of an infrared thermometer to test external cat temps and a manometer to check dpf differential sensor is reading true.

But, given the P0428 code, the cat temp data is the only one that looks within spec to me here!


So yes, thank you for getting through this post. I would be grateful for any feedback here at all.

cheers

[Huskyxantia]

Valve stem seals ? Gaskets in the turbo ? I'd enderscope anything that is a potential passage way for oil . The oil is going somewhere and if you no visible puddles under the van its got to be dumping it either out the tail pipe , maybe check the intercooler see if thats got any in it. Good luck hope you get to the result you want.

[DEVON DOGG]

The absolute madness of these modern vans is beyond comprehension

I have been through 3 engines on 3 different Boxers and they are made of butter .
We have never had them go this early but this madness takes us onto our next crazy scenario
We had one burning oil at around 50K and the Pug main dealer said that the Ad blue pump was faulty and changed it and then the problem stopped until 10 months later when the thing did blow up on 120K

Logic tells you that this would be a load of waffle but its not the first time I have heard of it

[JonnyBell]

Hi. thank you for the replies and apologies for the lack of update. Nothing has changed but taking to another mechanic this week.

there are absolutely no visible oil leaks. valve stem seal fault seems unliley with absoutely no other symptoms and no performance issues. similarly, no evidence of external turbo leak or turbo performance problems.

There is some residual oil in the intercooler pipe... i'd say 20ml max dribbled out one time, otherwise its just a coating inside the pipe. ive been told this is normal.

I'll be getting a compression test done this week to rule out pistons/rings, after that i'll be doing the pcv valve/rocker cover change and see where we are after that.

Still concerened with my NOX readings, but i'll ask mechanic to do a replacement part/adaptions reset on his diagnostic to double check its simply just not been done since nox sensor was changed.

I'll also be looking at the O2 sensor voltages with mechanics diagnostic tool and check fuel trims etc.

One interesting development is that about 400 miles ago i topped up the adblue (added 7 litres so was half full) on a whim as i'd heard low levels can cause mystery symptoms, and since then ive had no return of the P0428 code so far! lets see if that did the trick.

[GiveMeABreak]

@JonnyBell: I've deleted your other post as it duplicates what you have already posted here in your first post. Please don't create multiple posts for the same issue as it duplicates any answers / responses, thanks.

[JonnyBell]

@JonnyBell: I've deleted your other post as it duplicates what you have already posted here in your first post. Please don't create multiple posts for the same issue as it duplicates any answers / responses, thanks.

OK. Thanks for the correction

[JonnyBell]

Valve stem seals ? Gaskets in the turbo ? I'd enderscope anything that is a potential passage way for oil . The oil is going somewhere and if you no visible puddles under the van its got to be dumping it either out the tail pipe , maybe check the intercooler see if thats got any in it. Good luck hope you get to the result you want.

Forgot to quote. I have replied in the thread

[JonnyBell]

The absolute madness of these modern vans is beyond comprehension

I have been through 3 engines on 3 different Boxers and they are made of butter .
We have never had them go this early but this madness takes us onto our next crazy scenario
We had one burning oil at around 50K and the Pug main dealer said that the Ad blue pump was faulty and changed it and then the problem stopped until 10 months later when the thing did blow up on 120K


Logic tells you that this would be a load of waffle but its not the first time I have heard of it

Mental! How does problems with denox/Adblue affect oil consumption?

[Huskyxantia]

Hi. thank you for the replies and apologies for the lack of update. Nothing has changed but taking to another mechanic this week.

there are absolutely no visible oil leaks. valve stem seal fault seems unliley with absoutely no other symptoms and no performance issues. similarly, no evidence of external turbo leak or turbo performance problems.

There is some residual oil in the intercooler pipe... i'd say 20ml max dribbled out one time, otherwise its just a coating inside the pipe. ive been told this is normal.

I'll be getting a compression test done this week to rule out pistons/rings, after that i'll be doing the pcv valve/rocker cover change and see where we are after that.

Still concerened with my NOX readings, but i'll ask mechanic to do a replacement part/adaptions reset on his diagnostic to double check its simply just not been done since nox sensor was changed.

I'll also be looking at the O2 sensor voltages with mechanics diagnostic tool and check fuel trims etc.

One interesting development is that about 400 miles ago i topped up the adblue (added 7 litres so was half full) on a whim as i'd heard low levels can cause mystery symptoms, and since then ive had no return of the P0428 code so far! lets see if that did the trick.

Could be a software issue then , psa are know for this

[JonnyBell]

Hi. thank you for the replies and apologies for the lack of update. Nothing has changed but taking to another mechanic this week.

there are absolutely no visible oil leaks. valve stem seal fault seems unliley with absoutely no other symptoms and no performance issues. similarly, no evidence of external turbo leak or turbo performance problems.

There is some residual oil in the intercooler pipe... i'd say 20ml max dribbled out one time, otherwise its just a coating inside the pipe. ive been told this is normal.

I'll be getting a compression test done this week to rule out pistons/rings, after that i'll be doing the pcv valve/rocker cover change and see where we are after that.

Still concerened with my NOX readings, but i'll ask mechanic to do a replacement part/adaptions reset on his diagnostic to double check its simply just not been done since nox sensor was changed.

I'll also be looking at the O2 sensor voltages with mechanics diagnostic tool and check fuel trims etc.

One interesting development is that about 400 miles ago i topped up the adblue (added 7 litres so was half full) on a whim as i'd heard low levels can cause mystery symptoms, and since then ive had no return of the P0428 code so far! lets see if that did the trick.

Could be a software issue then , psa are know for this

The plot thickens

[GiveMeABreak]

Adblue will have zero to do with burning oil - it has nothing to do with the engine, end of. It only travels from the Adblue tank in pipes to the injection point at the Cat.

I suspect what he means is that if the Adblue injector has a leak, then it could be allowing UREA to seep onto the catalytic converter assembly where it will be smoking as it it burned off, which may be mistaken for oil, although it won't smell anything like oil, just like an ammonia.

[Huskyxantia]

Different scenario but weird psa things do happen , heres mine.

I've found that my dpf warning light comes on when fuel level is low when i open the tank cap the light will go out

[GiveMeABreak]

On some vehicles the fuel cap has a plug to detect when fuel may be added to the tank and this is used to inform the engine ECU to make a check to confirm is fuel was added and then to dose the tank with some additive in the correct amount.

So maybe the DPF is needing a regeneration...

[JonnyBell]

Adblue will have zero to do with burning oil - it has nothing to do with the engine, end of. It only travels from the Adblue tank in pipes to the injection point at the Cat.

I suspect what he means is that if the Adblue injector has a leak, then it could be allowing UREA to seep onto the catalytic converter assembly where it will be smoking as it it burned off, which may be mistaken for oil, although it won't smell anything like oil, just like an ammonia.

OK. Well for my case, I have no smoke at all from exhaust. No signs of Adblue leaking.

[JonnyBell]

On some vehicles the fuel cap has a plug to detect when fuel may be added to the tank and this is used to inform the engine ECU to make a check to confirm is fuel was added and then to dose the tank with some additive in the correct amount.

So maybe the DPF is needing a regeneration...

Yes I have heard this to be they way the elloys additive is added to the fuel... Something like it does it everytime you fill up due to a sensor at fuel filler... It was said that, by that rational, the elloys can be used up more (i.e. No calculation involved, just a set amount added with every trigger) on frequent low volume vs less frequent high volume