+- Rawze.com: Rawze's ISX Technical Discussion and more (http://rawze.com/forums)
+-- Forum: Big Truck Technical Discussion... (/forumdisplay.php?fid=1)
+--- Forum: Your Daily Blog (/forumdisplay.php?fid=77)
+--- Thread: VW 3.0 TDI (/showthread.php?tid=10421)
VW 3.0 TDI - jmartin - 12-03-2025
Starting this thread to document working on my VW 3.0 diesel. The experts on here may be able to weigh in now and then and keep me from doing something too stupid. Maybe there are others on here who own small automotive diesels who wish to maintain them properly and can benefit from such a discussion.
I picked up a very good deal on a 2012 VW Touareg TDI with 139k miles on it. The engine is the 225hp 3.0L CATA version with EGR/DPF/SCR.
Some reading material on this engine: 3.0 SSP
It runs and drives "fine" but of course suffers from "deferred maintenance" like every used euro vehicle here. The plan is to start with an EGR tune up and fix the minor issues found so far.
-No stored engine or emissions codes
-RPM/boost dependent turbo whistle
-Exhaust leak from engine bay at startup and standstill with engine running
-Slight RPM fluctuation at idle at times
The "turbo pulsation damper" seal (at turbo inlet) was leaking, as was at least one of the intercooler connections. I'm going through the intake system and replacing all the orings and seals which I hope will fix the turbo whistle. Turbo itself feels ok - I cannot feel any movement in the turbine bearing, either axial or radial. There is a significant amount of oil in the charge air piping - I drained a cup out of one of the intercoolers. Not sure if that's normal for these engines or if the oil separator has failed - no PCV on these.
Think I found the exhaust leak source - there is a crack in the EGR flex pipe coming from the turbo pedestal. What's interesting about this pipe is it contains a mini-DOC which is supposed to burn up soot before it gets into the intake. Unfortunately that little sucker is expensive - currently $600+ from VW. Seems they are known to crack, maybe due to the heat cycling caused by that catalyst. It doesn't look very fun to replace.
This engine has 4 timing chains located at the back of the engine. Chain stretch is a known issue on these, which I blame on the low-SAPS 5w50 or 5w30 oil spec on long intervals. Maybe there are other factors as well. Fortunately, it is easy to check chain wear via an adaptation value. Mine shows around +4.3 degrees (new engine would be at 0 deg). I'm told they can generally get to +7 before you need to start thinking about replacing them. There is zero chain rattle at startup. Obviously the goal is to slow the chain wear rate as much as is possible going forward, hence my comments in the "gear lube in engine oil" thread. Thinking I will either go with Rotella T6 (5w40 or 14w40) + 10% GL5, or Motul X-power 10W60. The Motul oil appears to be higher SAPS and most importantly can be purchased from a certain Euro parts supplier that offers lifetime warranty on everything they sell including engine oil - the savings can be substantial. You can do regular maintenance for the cost of return shipping the filters/oil etc back to them.
Enough for now... I will try to update here as I go through EGR tuneup and maintenance etc.
RE: VW 3.0 TDI - Rawze - 12-03-2025
#1 cause of turbo leaking oil into CAC or exhaust is excessive crank case pressure, not the turbo face seal. Sure the seal wears over time, but it should typically never leak unless something causes it. Most common causes are either crank case pressure, or a vacuum at the intake manifold of the engine due to various reasons.
Also, if the crank case is ventilating into the inlet of the turbo (a lot of euro cars are designed this way as "no oil fumes" emissions garbage rules) ... then that is the FIRST THING that has to go!. Vent it to atmosphere (unless your in one of those countries where its illegal ehemm). - That is one of the worst things that you can do to a diesel engine!... and especially so, if it has EGR on it. .. ans the pi## poor excuse of 're-burning the fumes' is just that!. An unmeasurable excuse that is NOT worth trying to reclaim vs. all the nasty gunking up of the turbo, CAC, intake, and valves, killing off the intake flow, dropping fuel mileage greatly over time + other issues as a result.
just my own thoughts, .. the beer is talkin'
RE: VW 3.0 TDI - mikkhh - Yesterday
I do not know a single 2000 + european diesel car engine that does NOT have pressurized crank case breather and that does NOT route oil fumes to turbo inlet.
They all have, but positive pressure in crank case is no good, it will cause top end oil starvation, issues with turbo oil draining and so on.
If you just route pcv to atmosphere it may not cure oil consumption issues, since there is a valve that opens when there is too big crank case pressure.
BUT the PCV IS LOCATED UNDER THE EGR COOLER, takes couple of hours to get to it. Or you can just drill hole into oil cap and route away that way and blank the line going to intake. I assume you want to keep this car for a couple of years, in that case replace oil cooler seals and also seals between oil cooler and engine block. Also remove egr cooler and clean it. Also remove intakes and clean them. I clean intake manifolds and egr coolers in 30l cheap ultrasonic cleaner (with engine degreaser or oven cleaner), to make process faster first clean is done using high temperature pressure washer, that gets most gunk cleaned up. You may need new swirl flap linkages, since they get worn and fall off. You should remove injectors and replace injector copper seals + O rings, since those injectors are located in oil basically, if copper seal goes out (and you do not notice by sound) you will start leaking soot/carbon into engine oil, that can wipe out the engine. It is way easier to swap injector copper washers if injectors are not sooted stuck and there is no huge mess to clean up. Injectors wise it is very important that you do not use those injector seat cutters, there is ABSOLUTELY no need to cut them if there is no visible grooves worn in from leaking injectors, but that is like very very rare and takes lots of neglect for it to get that bad. If you absolutely have to cut injector seats you MUST compensate with thicker injector washer so the injector tip stays same height regards to cylinder head surface as it was before.
What software version is on ecu? If they have later dieselgate software fixes those things run absolutely crap and gearbox also goes jerky. It is absolutely reccomended to reflash both gearbox and ecu back to the software it was running 10 years ago.
What about injectors? On those engines most common issue with injectors is that nozzles start to drip. If electrical part (piezo) is failed then the engine would cut out randomly or will not start at all since those injectors are high voltage. If you have excessive injector leak to return line then the engine will have issues starting and long cranking, if you get engine started then it is going to run fine and you can not tell that something is off. If injectors are faulty then do not have them refurbed (even by b0sch) or buy cheap knock off's, neither one is going to last properly. I would buy either brand new ones or good used ones from a junk yard for 1/6th the price of a new one. I do not take them to bench testing, I just install then in the air with only high pressure line connected on car keeping old injector clamped down and return line connected (since there is 5bar fuel coming to return line) and just crank engine for like 10 seconds or more to see if nozzle goes wet or there is any big visible dripping at return line, if not then 99% times the injector is fine and will work. Why I do not take them to have them bench tested? First of all most bench testers do not check injector regarding to specs on injector specific IMA code and bench testing is done at only like room temperature compared the temperature the engine is facing and most do not give new IMA codes AND bench testing costs like half the price of used injector, sometimes even more. I get along with local yunk yard guy and if the injectors he sold me is faulty right away he will give me another one and he allows me to test injectors at his place and if he has a new car for dismantling I can just hook up scan tool and check those injector correction times, if they are ok and there is no excessive injector return happening then I can use those injectors just fine.
IF intake manifold is cleaned properly, swirl flap linkages have not fallen off and engine is healthy then looking at injector correction time uS values (they start from like measuring block 70), they should not have - signs in front of them and if they have like -10 -20 then there is something wrong with the injector.
Your engine is hardware wise same design as the first 2004-5 3.0tdi, except you have the newer high fuel pressure pump that sometimes likes to create metal shavings, since there are only two pump heads instead of three like the first ones that were absolutely bulletproof. I have seen old ones leak (usually it is not seals, the covers are just warped), but never wreak havoc like newer styles.
Oil wise I see no reason to use that expensive 10w60 "racing" oil in my cars. Good old truck 15w40 mineral or 10w40 semi synthetic / mineral + gear oil will work just fine. I buy truck oil by drum so it is cheaper to 5l or 20l jugs of 10w60. When I was younger I ran that 15w40/10w40 truck oil in wet clutched 140cc/160cc pit bikes (never had any oil related issues there or wet clutch, those oldschool 70s design air cooler vertical engines took abuse well and also forgave almost everything repair wise, chinese cheap engine parts worked just fine there), to this day I still run atf in my 250 2 stroke mx bikes transmissions and use chainsaw premix oil. I am not racing those 20-30 year old bikes so I an not worried. I have not ridden those bikes for more than two years. Project 97 yz250 is in pieces waiting for an overhaul - new used forks and shocks (since old ones have damaged chrome shafts) and engine is in pieces also, looking up bearings for cheap. Bought it just to give it a second chance, but parts cost is astronomical (and there are no new parts available for everything) and the amount of work required also, looking for a newer grenaded engine 4stroke mx bike to get the front fork and rear shock for cheap. Second 250cc 2stroke bike is just fill up gas and run it.
Those first generation 3.0tdi had way less issues than newer ones - there is usually no leaks between top oil pan and engine block, newer ones are notorious for that and bolts between engine block and top oil pan are ALUMINIUM, the fix was to reseal with RTV like factory and at least replace longer bolts with stainless bolts.
In europe there are quite a few early 3.0tdi that have driven 500 000 km with original timing chains without the need to replace them...
Take a look at harmonic balancer, they have issues and get worn with age and start creating more vibrations and also they are going to play a role in timing chain life expectancy.
I believe that the reason why those chain issues were so big was because injectors were dripping and that caused way low crank angles and those 3.0tdi engines that have spun bearings have had all either leaky injector(s) or really bad programming. Also when engine is in dpf or scr warmup mode timing gets advanced and that is going to also cause increased strain on timing chains.
My daily driver om642 engine car has 500 000km on it, still original chains, it has still got dpf and other stuff...
I know two (one with dpf and other without dpf but has had stupid power box on it whole it's life) Jeep OM642 grand cherokees that have 500 000km and still original chain, yes the tensioner has moved compared to new chain, there is no cold start rattle or anything, but chain on the stock car has still got plenty of life left and it does not make sense now to swap it on a 20 year old car with some aftermarket part that may last lest than the one that is on it now and the new original costs 500, suppousedly iwis (the manufacturer who makes chains) 100, car itself costed 2500 two years ago, other one was 2000. It was around 100 in gaskets to fix the oil cooler leaks and clean intake manifolds. I will pull the intakes on dpf equipped jeep to clean them, there is no oil cooler leaks visible so they have been cleaned some time in the past, but car is low on power compared to another jeep (that had tuning on it and jumped timing chain) that is stock programming now and chain has been swapped and intake has been cleaned.
Powerbox tuning Jeep engine I will pull apart completely to see how pistons look, how the bearings look. No idea when acutally, but when I do will post pictures here. Most likely will pull apart other engines I have since I want to use those engines on newer cars that have way way worse engines (plastic intakes, rocker covers and so on) and really bad parts availability.
Some of those 3.0tdi will get stuck at high idle after deman and that will happen even like year later. And the guys doing d3letes on them are absolutely clueless why, they have no idea about those warmup modes and that is the actual reason why engine ends up at high idle (to warm up now missing cans). NOBOBY who does "deman" them knows how to edit timings to compensate for missing exhaust gas, they just crudely tell e g r valve to not open anymore and delete all fault codes.
What is even worse, guys who tune them raise rail pressures to OBLIVION, advance timings even more (although there is no egr gas anymore so the final crank angle is already lower) and soon after engine will have rattling timing chains or in the case of newer generations of 3.0tdi the bearings get spun first. They start telling stories how bad those 3.0tdi engines ( and every other newer engine that they touched) are and so on. They have zero clue what deSox and deNox functions to on cars and why actually there are O2 sensors on diesel cars. I did not read all that audi page now but, D4204T5 engine page 38 explains the concepts well enough. That is also the reason why engines start smelling bad after butchering the cans - maybe engine is trying to carry out deNox by injecting now unneccesary fuel to exhaust...
What happened with dieselgate was that manufacturers used Auxiliary Emissions System clauses to avoid using e gr so there will be less soot and dpf filters will last longer and have less frequent regens. I had 2.0tdi commonrail passat with 800 000 km years ago that had dieselgate sw still on it and it had NEVER been to dealer. The intake manifold looked quite fine after all those km and there was no massive carbon like on newer cars that have like only 100 000km on them. I will do intake clean maybe this weekend on 2.0tdi that has same kind of engine but has had dieselgate software update done it at like 20 000km, and has driven 100 000km after that. Well the dpf failed shortly after (sooty tailpipes) and dealership told while car was still under warranty that it is normal. The cars that have not had software fix still have healthy dpf s even after lots of kilometers.
RE: VW 3.0 TDI - jmartin - Yesterday
@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?
RE: VW 3.0 TDI - mikkhh - Yesterday
(Yesterday )jmartin Wrote: @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.
All older engines do not have any crank case filtration, just a long pipe and usually steel mesh as a filter at cylinder head, the amount of dirt or unfiltered air coming down a like a meter long tube is neglible.
(Yesterday )jmartin Wrote: @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.
Never used then or heard somebody using them, most guys here have no idea that crank case breathers may have filters.
(Yesterday )jmartin Wrote: 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?
Well Europe I have never seen those older 3.0tdi with SCR and on newer SCR equipped vehicles I have never heard anything about replacing SCR catalysts, sometimes nOx sensors get replaced with software update and then there is no reverting to older software with new part code sensors! That thing I overlooked and it is MUST CHECK. 1.6tdi had some tube installed just between MAF and air filter box, but those old pre 2015 never had SCR in my area. I have heard of some German market 2005 era Vag having scr and or some dpf fluid like Eolys on French cars.
Yes the program you mentioned makes it possible, you need older sw flash files, some are really really hard to get ahold of.
(Yesterday )jmartin Wrote: 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?Are those part numbers interchangeable by cross reference? Also there were no pressure sensing glow plugs on 3.0tdi in our market. Can you check for maximum rail pressure while driving? It is most likelt more than 1800bar I quess. Most likely they changed engine to use HCCI combustion.
(Yesterday )jmartin Wrote: 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.
https://www.youtube.com/watch?v=0Cz51u2KqBM no idea how good video and so on but looks similar to yours?
Oil cooler seals I mentioned, since they do not cost much and since you have the valley open anyways it makes sense to prevent those issues from happening. Earlier 20 year old 3.0tdi that have similar design to yours have valley leaks around here. There is coolant T between top part visible in valley that is notorious for breaking.
In Europe ASB engine was from like 2004-2008 and I have never heard them having SCR, earliest ones did not have dpf even, like the one I had that was bought new from Italy.
CNRB is the later style 3.0tdi that first appeared in around 2012 - it has way more issues than older ones like yours. For example common leak point between upper oil pan and engine block, timing chains that wear out faster than on older ones, V valley oil and COOLANT leaks super common, also front engine cover leaks, thermostat/oil cooler leaks and so on also the occasional high pressure pump grenades and snapped turbo shafts (most likely due to neglect and abuse). That style engine had scr on them in Europe starting from like 2016+ revisions.
(Yesterday )jmartin Wrote: 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.Swirl flap linkages are external and now there is repair kit available for those that costs like 30 from dealer. Swirl flap motor failures were also very common.
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.
(Yesterday )jmartin Wrote: 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?Common theme with those CP4 disasters is guys who ran their fuel tank below 1/4 level all the time and also just keep filling up by 5-10l at gas station.
(Yesterday )jmartin Wrote: 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.If the rubber part is cracked visibly it is going to throw off the belt and leaves you stranded. Maybe you can send a picture?
(Yesterday )jmartin Wrote: 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.
Most OM642 have failed AFTER oil cooler seals or oil cooler change. 642 engine oiling system is oil pump -> oil filter -> OIL COOLER -> turbo, bearings . Most engines have filter after the oil cooler. You need to be meticulously clean to avoid disaster there, and absolutely avoid aftermarket oil coolers, they usually create aluminium shavings and bearing damage follows soon after disastrous contamination. I have fitted aftermarket oil coolers with filter housing to 651 engines, I ran it for like couple of minutes and then changed oil. The oil filter looked like engine had bearing damage. After that it cleared up and four years later that engine is still working like it should. I have heard other stories of aluminum shavings coming from cheap oil coolers. I have seen one Sprinter with om642 that had 1 000 000 km on it three years ago, the mileage stopped counting up and needed start at zero to keep track of oil changes. Injectors were replaced at 800 000km, injectors wiped out the dpf too. I have pulled apart bearing failure 642 engines, they all look really neglected inside and heavily sooted up, also pistons look terrible with obvious fuel impingement issues, most likely engine tuned to oblivion. Some 642 develop oil consumption issues, most of the time small consumption due to crank case breather and camshaft seal leaking badly and passing oil from oil separator/centrifuge located on camshaft). Big oil consumption on those usually originates from piston oil control rings clogged up due to lack of maintenance, BUT newer 642 have aluminium block with some electro or whatever coating and that wears off just like on benz petrol engines. Then it is either block replacement time or have it resleeved to fit cast iron/steel sleeves. Not easy to find somebody who can resleeve engine block properly nowadays. Latest 642 engines have single row timing chains and I have heard of camshafts snapping during warranty period even, but highly uncommon.
(Yesterday )jmartin Wrote: 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.
Has anybody checked injectors on failed ecodiesel? How nasty intake looks? Was the intake swirl flap motor gear still okay?
That factory tooling worn stuff I highly doubt, seriously wrong bearing clearances in an engine would fail really fast. Modern manufacturing is pretty good and big manufacturers have proper quality control for the most part. I have yet to pull apart a working ecodiesel engine to see if crankshaft is getting curved and is that the reason for bearing failures originating from mains? Warped crank can distort the engine block/main caps too, like on 646 mercs. There was some info about oil change on ecodiesels to 5w40 that happened in those 2016+ ones.
(Yesterday )jmartin Wrote: 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?
First of the problem lies in lack of proper tools and definition files. Logic flows are also hard to find. Only proper way I think to do them is to find matching software and description and just link them together. I do not know anybody who has built a proper deman for them. Lots of butchers out there who raise low rpm TORQUE to oblivion and deman by deleting dtc's and sometimes even whole dtc table and as bonus sometimes glow plugs also get deactivated. Those guys have ZERO clue that catalytic converters are actually active parts that are constantly regenerated.