VW 3.0 TDI

[jmartin]

@rawze - yes it has the typical euro setup with crankcase vacuum pulled from turbo inlet thru an oil separator. I do not want the oil in there, but the problem with vent to atmosphere is when the hot engine cools down it will suck unfiltered air thru the breather tube and bring dust/dirt into the oil. Could put a breather filter on the end of the tube and that might be good enough. Also some factory separator designs require a little vacuum to open - if there is no vacuum they will build high crankcase pressure. Don't know if this one works like that. I may just go with a catch can setup and NOT set it up to drain into the sump.

@mikkhh - Do you have experience with the Mann & Hummel Provent? Seems they are used more in EU and Australia and designed for diesels. It has a coalescing replaceable filter.

Yes, this one had the dieselgate fix done, back in oct 2019 at 68k miles. Sticker under hood indicates the SCR cat was replaced with a new PN, but DOC/DPF are original.

I would REALLY like to revert to pre-fix software. How can I get this done? Possible with ODIS-E?

The two cylinder pressure sensing glowplugs were replaced with updated PNs as well. I think that is it for hardware modifications - would the pre-fix software work just fine with the revised SCR cat and cyl pressure sensors?

Regarding the oil cooler - there is no leak in the valley. I know the valley reseal is a common thing on the CNRB, but it seems to be much more rare on the CATA. Very easy to find many videos of people doing the CNRB valley job, very very few videos of that job being done on the CATA, if any. And in fact, it appears the cooler gasket is a metal one rather than the soft seals on the CNRB. The design and layout of components in the V is quite different in the CATA compared to the CNRB. CP4 is at front, driven by toothed belt, oil filter housing is in a different place, coolers are different, etc etc. The CATA also has an aluminum upper intake manifold, CNRB is plastic. That is not accurately depicted in the document I linked in the first post. If I am not mistaken, the CATA is much closer to the CASA that was used in Europe, rather than the CNRB. Perhaps the CASA was a non-SCR engine? I am sure you have much more knowledge on it.

I will inspect the intake manifolds for carbon buildup, and likely at least pull the upper one regardless to get a good look at everything and I want to make sure the swirl flaps are in good shape. In theory, since it has a DOC in the EGR flow path it should greatly slow down soot buildup compared to CNRB.

When I get through this other stuff I will do return flow tests on injectors and I will note your advice to replace the copper washers - it is not difficult or expensive so might as well get it done. I have not checked correction values yet, that's on the list. I did verify that all injector codes programmed into the ECM match the codes printed on the injector and they are all in the correct positions.

CP4 fuel pump is what has me most concerned - how do I keep it alive? I know they are extremely sensitive to contamination so filter needs to be OEM and not neglected. They also HATE air in fuel - very important to run purge cycle from scan tool before starting engine after filter changes or opening the system. Trying to decide if I will bother with an additive like Power Service. Many CP4 make it to hundreds of thousands of miles with never a drop of additive. Others get additives and still don't survive. US fuel is supposedly lower quality and cetane rating than in EU. Is it worth installing a "disaster prevention kit" that adds a filter and reroutes pump case fuel away from injectors with intent to save injectors if pump fails?

Harmonic balancer is likely original. What mileage interval should it be replaced at? Appears to be a $500 part so I don't want to throw one at it unless there is good reason to.

Your OM642... I was also looking at ML350s with that engine. Here in the states they die needlessly from lack of maintenance. I feel they are solid engines and are 500K mile capable with proper care. Some lose main/rod bearings - I think this is because the hamfisted apes that work on them don't realize that you have to be extremely careful to keep contamination out of the ports when doing an oil cooler reseal - those ports will carry dirt straight to the bearings.

The VM 3.0 Ecodiesel. Here, they either run forever or die young from snapped cranks or seized bearings. A friend owns a 2016 in a Ram truck that has 270k miles on it, still sounds and runs great. As you said, the big issue is parts availability - Stellantis absolutely doesn't want to support them anymore. Good used ones can be $7k or more. I was told that the factory did not replace tooling often enough so cranks got out of spec and led to failures, often at less than 100k miles. If you had a good one it was fine. The pressed on cam sprocket also led to failures for some of them. 2014 was first year for them in the USA and the 14s and 15s seem to have higher incidence of crank failures compared to 2016+. Software changes may be a factor.

And finally.... is it possible to develop a proper demandate for the VAG 3.0 TDI? I suppose the calibration tool, OEM definition files, and a knowledge of how the logic flows would be needed to start with, and presumably those resources are not available "in the wild"? Or does enough of that exist that if a person was willing to put in the work it would be possible to build a safe deman calibration?