Oil level rising VW Sharan 2015 2.0 TDI 103KW

[davey_boy]

Hi Guys, ive owned the car for about 18 months, having to change the oil approx every 5000 miles as level rising. Any ideas? Ive heard there might be an issue with excess diesel entering sump through DPF process, when i checked loading figures through VCDS it seemed fine. Oil coulour seems normal. Any ideas/ pointers? Obvously worried about oil degredation and major component failure

[Crasher]

What is the VIN?

[davey_boy]

Hi Crasher, its Wvwzzz7nzfv041010

[davey_boy]

Car has done 65K miles

[Crasher]

Your truck is at the end of the seriously problematic under floor SCR system which caused notorious trouble and is subject to so many issues.

[davey_boy]

Thanks for the info crasher, any pointers or advice on solving?

[davey_boy]

Am i right in saying that the oil level rising is due to excess fuel (injected during exhaust cycle when regening)getting into sump, thus leading to logical conclusion that regen is occuring too often? I've read a few bits suggesting roll back of the dieselgate software 'fix' might help to reduce dpf regeneration frequency, do you think this is worthwhile? Can the high frequency regenning be a symptom of blocked scr cat? . I read some of posts about the leaking adblu injector issue, do you think replacing this injector is a worthwhile mod in any case? Is there an easy way to check if scr cat is blocked?

[Crasher]

The usual cause of problems is the SCR unit getting blocked with urea crystals due to the reductant injector dribbling. This makes the ECU think the DPF upstream is blocked so it is constantly trying to regenerate. The first step is a code read and then viewing of the soot loading figure. If this is around 40% then a forced regeneration needs to be carried out whilst driving. When this is finished at approx 3%, the ignition should be cycled and the soot figure viewed again. If it has gone back up to around 25% it is likely the SCR is blocked and will need replacing as they cannot be successfully cleaned as often the primary monolith collapses. Because of this and the relative scarcity of these cars in VW and Seat form they are very difficult to find used, the people we use for cleaning DPF Clean Team are always on the lookout for these and they fetch good money. To confirm the diagnosis we take the reductant injector out of the SCR and use an endoscope to inspect the insides.

[davey_boy]

Your input is very much appreciated Crasher. I'll have a play this weekend. Are there any trustworthy aftermarket SCR cat brands you'd recommend? Or is it oem all the way for this?

[Crasher]

The only one I would consider is the Ernst 761000 but it is getting one that is the problem.


https://digital-assets.tecalliance.services/images/3200/4fe46d190574749be629ec41cdbbddcd938387de.jpg?ver=3 .69.0.a716c61eb6

[davey_boy]

Cheers Crasher. When looking into the cat with the scope, is it absolutely obvious when the unit is beyond cleaning/regeneration? There's no rattling that I'm aware of so I'm wondering if I've maybe caught it in time, prior to collapse?

[Crasher]

I meant to save a picture last time but yes it is pretty obvious when blocked as you can see open channels and those blocked with grey crystals, usually in the lower section and sides.

[davey_boy]

3902539026photos of the SCR filter

[davey_boy]

I put the scope up yesterday, adblue injector and its orrifice were clean as a whistle which i was surprised about, but the filter looks pretty clogged, is this what you saw on your unit, Crasher? I noticed that theres a fan like baffle welded into the SCR between the injector orrifice and the monolithic filter , i'm assuming thats why the cleaning guys say the unit cant be cleaned (with high pressure)?? I'm thinking i'll take the unit off and soak it with acidic cleaner, or worst case, cut the weld open and blast it directly with high pressure. Ive ordered a new Bosch Adblue injector too. Crasher, have you heard of anyone having any luck with an off-vehicle clean?

[davey_boy]

39027photo of the baffle welded in between the injector and the monolith

[Crasher]

That is designed to impart a swirl in the gases, that one is cleaner than the one we did a few weeks ago, you couldn’t see the lower 1/4 monolith.

[mickeybo]

The very very most likely place of oil mixing with water has to be the cyl head its self

[davey_boy]

I took the pipe off the car at the weekend and soaked it in 10% Hydrochloric acid for ~2hrs. Looking in with the endoscope wasn't giving the clearest picture so i decided to open up the pipe. Acid seems to have done the trick. Hopefully the active elements are still in place on the monolith. I will report back on performance once i refit. Getting the pipe off was a pig. The 3 retaining nuts were rusted to almost nothing, used the heat -up and rapid cooling method, then a nut removal tool. 2 came off ok, the 3rd snapped the captive bolt on the DOC downpipe, had a lovely time drilling that out. What an absolute crap design.39035 39034

[davey_boy]

someone kindly messaged me the link below on urea crystal removal

https://patents.google.com/patent/CN103111445A/en

[davey_boy]

Background on the 2.0L diesel engines at the core of the Volkswagen emissions testing debacle - Green Car Congress (https://www.greencarcongress.com/2015/09/20150921-vw2l.html)

An interesting article detailing the many components and multiple regeneration modes used for the different catalysts/filters in the exhaust system. If your driving use-case does not involve frequent long journeys, these modern diesel cars are not fit for purpose

[Crasher]

My life seems to be nothing but blocked DPF's and SCR cats, two in at the moment and another tomorrow, 2018 A6 Ultra blocked SCR... absolutely **** idea forced on us by EU numpties.

[davey_boy]

Thanks again for your input Crasher, you and others make this forum a very valuable resource. The wife had a Ford for a while and the associated forums are garbage compared to this one. Anyway, I'm about 500 miles post fix and, touch wood......all is well.

[davey_boy]

Quick update, car flew through the MOT yesterday so seemingly the active SCR elements are still in tact

[davey_boy]

Update: issues continued with the constant regenning. I compared live data pressure differential data for the DPF between the Sharan (2015 ~70K miles) and my Tiguan (2010 ~140K miles). The Tiguan has the early generation of the same engine with no SCR. Pressure differential figures were very similar, however the Tiguan was running fine and hadn't even attempted to run a regen for 700 miles. I figured that the DPF and associated control system on the Sharan were a lost cause and opted to have it removed. DPF, Ad blue and EGR were coded out and EGR blocked off. (DOC and SCR left in place) Probably 1000 miles down the road now, and apart from the acrid smell out the tailpipe, the car seems reliable (....touches wood whilst typing!!)