Why the 3.2 platform chains stretch... or do they? The truth is out there!

Discussion in 'VR5, VR6 & Wx' started by G60Dub, Jan 22, 2018.

  1. G60Dub

    G60Dub Forum Member

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    PLEASE ALSO READ POST 11 BELOW - IMPORTANT UPDATES!

    Chain document now uploaded - 1st May 2018 - It's not to the standard I would like but it's readable after a fashion.


    Though it prudent to post up some well needed info on our 3.2 & 24V motors and chain and guide wear that seems inherent on these platforms. All of this is gleaned from German forums (links provided at the end of the post)

    After having replaced my chains and guides a couple of years ago I became interested in why these engines appear to suffer from this condition. The necessitated crawling around many German VAG forums in an attempt to acertain if there was any solid knowledge out there as to why this condition appears to pervade the 3.2 platform.

    What I (eventually) discovered was an utter eye opener the cause was well known and several well educated Germans collaborated on objectively analyzing the spate of broken timing chains and the stretching of others.

    Ill provide a quick synopsis here on chains snapping and chain stretch, the latter being attributed to several combinations of factors and the former having one further factor added.

    Given the vehicles increased blowby and larger heat sink volume including 5.5L of oil and 9L of coolant the warmup phase in this engine is typically longer than smaller displacement engines from the threads below around 12 miles is stated.

    Apparently both Longlife II and Longlife III oils have an extremely low TBN resulting in reduced protection against acidic blowby product during the engines long warmup phase.

    With typical fixed service intervals of this results in acidic by products building up to excessive levels in the oil causing acidic corrosion and also hydrogen embrittlement of the chains, sprockets and guides.

    Another well-known issue is the sludge build-up caused by high evaporation loss and Zinc in the additives package. Seemingly this is a well-known issue across the industry with Castrol Longlife oils.

    With extended Longlife service intervals and mainly short journeys the oil pump pressure release value (On MK4 and MK5 R32) becomes blocked putting excessive pressure on the chain and guides which may cause rapid chain or guide wear. This is further compounded by the glass-fibre in the guides themselves being introduced to the oil rapidly accelerating the process.

    Now for the chains: Chains were originally made by Sachs but manufacture was changed to IWIS after multiple cases of chains snapping were reported causes at the time were unknown. The original Sachs chains were stamped with the manufacturers name causing stress risers which coupled with the Hydrogen embrittlement given extended service intervals was a ticking time bomb. As can be seen in the collected data in the chain report PDF there was a particular production month that appeared to be particularly susceptible to chains breaking.


    To illustrate one of the points above this is a picture of my head at 138,000 miles after using Longlife Oil at 5-6000 mile service intervals from 101000 miles. The engine was typically used for 36 mile round trip to work Monday to Friday and two long drives (130 miles each way) to and from work on a Friday and Monday morning comprising for the most part of constant A road and motorway driving. One short journey per week was made to the shops. Upon removing the rocker cover I was utterly shocked to see this mess:

    DSC00035_zpsoctwnewy.jpg
    .
    The chain report is in German and is long! It is a protected PDF but can be saved/printed to PDF and then translated to English - A TRANSLATED VERSION HAS BEEN UPLOADED 1st May 2018. IT IS worth the read! At the time this made the German media the report has from what I can tell been successfully used in several cost claims against Audi. A further point to note is that this issue was well known to Audi and early on they offered 100% free replacement of the entire chain system.

    Points to note: There is a PDF report and also a DVD/download. The latter gives video examples of healthy and damaged vehicles and the noises to be aware of.

    If you don't speak German open these in Chrome and have it translate it for you:


    Chain experiences (This gets very interesting around page 185 onward:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=2825&pageNo=228


    Master thread:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=5496

    Main Report threads:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=6440
    ...which links to (Timing chain report and DVD downloads can both be found at the end of post 1):
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=6148

    The PDF report:
    http://www.a3quattro-forum.de/pdf/Bericht_VR6_3-2_Kettentrieb_onlineVers.pdf

    Other threads of interest:

    Why we get sooty tailpipes:
    http://www.a3quattro-forum.de/index.php?page=Thread&postID=76144#post76144

    ME7 Load and ignition angle bug causing chain stretch:
    http://www.a3quattro-forum.de/index.php?page=Thread&postID=99429#post99429

    How long it takes for the 3.2 R32 to properly warm up:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=7832

    How to manually check chains:
    http://www.a3quattro-forum.de/pdf/a3q_steuerkettenbericht_update1-0-0.pdf

    Engine Oil FAQ:
    http://www.a3quattro.de/index.php?page=Thread&threadID=6568

    Excellent post with Oil anaylsys (Which oil for the 3.2):
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=2144&pageNo=26

    short updates post oil anaylys:
    http://www.a3quattro.de/index.php?page=Thread&postID=98316#post98316

    Bad Cam timing value re not always stretched chains:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=15012

    Why the MAF values pulse post SSR switch:
    http://www.a3quattro.de/index.php?page=Thread&threadID=2876&pageNo=1&81518284
     

    Attached Files:

    Last edited: May 1, 2018
  2. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Contact mat_mk3 and he can get it on our server.
     
  3. G60Dub

    G60Dub Forum Member

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    Hi Eddie

    It may take me a couple of weeks to get it presentable - Google Translate is rough! With it being 157 pages long I have a lot of rewording, photos to copy over and reformatting.

    Currently on page 37 of 157 (24/1/18)

    I'll keep this post updated with progress:

    Currently on page 92 of 157 (27/01/18)

    Currently on page 139 of 157 (03/02/2018)

    Currently finished as well as can be expected without extensive support from my Mrs (02/03/2018)
     
    Last edited: Mar 2, 2018
  4. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    I need to read through the opinions from that forum and see how it compares to the cars I drive and own here, 2.3 V5 20v, 2.8 V6 24v and 3.2 V6 24v.

    Should give us something to discuss for sure.
     
  5. G60Dub

    G60Dub Forum Member

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    Post 3 Updated^^ Matthew you have a PM.
     
    Last edited: Mar 2, 2018
  6. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    My observations are:
    I have seen more EU3 2.8 24v with the problem of chain breakage between 110k to 120k including stretch, than 3.2 engines.
    Chain stretch more on 120K + 3.2 rather than breakage.
    Chain stretch on our EU3 AQN 2.3 also after 140K miles.

    Chain stretch on the upper chain. Lower 12v chain arrangement seems fine.

    Some oilpump/upper drive 066 gears have been known to be affected.
    They have been replace as a matter of course on my 3.2T build.

    EU2 VVT intake only engines like say the AUE and the early RSI 3.2 not included in these comments.
     
  7. G60Dub

    G60Dub Forum Member

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    Iv'e spoken to Michael Lorch (one of the report authors) and he has granted permission for us to share the translated document on the forum. I've tried PMing Mat but not had a reply.
     
  8. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    I will point Mat to this thread.

    Not sure if he has seen his pm here.
     
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  9. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    I should also point out, the articles in those forums, while it contains folks actually going out to capture their observations, it is very specific to the A3 and the BDB EU4 engine which has some carry over parts from the BHE and BFH and other engines found in the Touareg of the same era.

    I now have an EU3 engine'd BHE car in turbo form and stuff like this is being observed and will be reported.


    I am not sure I have seen any parallels to what was observed by that forum as I not only own a 3.2 VR6 car, but also late 2.8 24v and 2.3 20v 5 cylinder also.
    These all share common components.
     
  10. G60Dub

    G60Dub Forum Member

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    I've read the entire Chain Stretch thread over the last few months and it get very interesting around page 200, so much so I pushed on quite hard and read the remaining 30 odd pages. The forum members have been actively involved with IWIS and I have important updates to add to the first post when I get a chance. Been spannering all day today so will do this tomorrow evening.
     
  11. G60Dub

    G60Dub Forum Member

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    Okay I've added the following link to the first post as it gets VERY interesting from about page 185 onward:
    http://www.a3quattro-forum.de/index.php?page=Thread&threadID=2825&pageNo=228

    Anyway to surmise very briefly:

    200 odd chains that had been replaced were sent to IWIS for inspection and subsequently measured; the eye opener; almost all of them were within factory tolerance! I do not know the spread of chains from the MK4/MK5 and Audi 3.2 platforms or if this information was recorded - I will ask the next time I speak to the relevant people.

    There is an issue with the oil pressure relief valve in the MK4/MK5 oil pumps that does not seem to be an issue with later AUDI 3.2 engines. This means that chain stretch (or accelerated guide wear) may or may not still be an issue with the MK4 and MK5 Golf platforms. Hence they strongly recommend if replacing the chains on a MK4/MK5 that the oil pressure MUST be checked using the M10 takeoff on the filter housing with the engine stone cold - should be 5.5 bar +-0.5 bar at 2000RPM. If its say 6.5 bar or over the oil pump is code F and needs replaced.

    However given the fact that the chains returned to IWIS was almost all still in spec had the forum members begin to suspect something esle was at play. With the recent (some years ago now) advent of the issue with VVT wheels giving up the ghost en-masse on the 1.4 TFSI they began to disassemble failed VVT wheels initially on the 1.4 and then progressively turned their attention back to the 3.2 VVT Variators.

    Coupled with the chain measurement results from IWIS, the stark shortcomings of the factory specified Longlife Oil and apparent failures on VVT wheels due to contamination and sludge buildup they turned to their counterparts in the oil production industry. After some consultation it was then decided was to try some preliminary flushing testing on select vehicles beginning with an initial 'hardcore' flush. This is accomplished using a sludge remover flush with the oil/filter then being replaced with a quality oil with a high detergents package. Immediately on the fresh oil and filter (in some cases up to 4 times ) a specific cleaning additive was added to the oil and a short driving regimen strictly followed, at which point the oil was dropped and a new filter/oil added. There are many supporting claims on the forum that this appears, in the majority of cases (but not all) to be extremely successful in reducing chain values in blocks 208 and 209 and in one specific case from -8 -8 to 0 -2!

    The information is simply provided only so that everyone that does not speak German can access it and then draw your own conclusions - This has taken me a lot of time and effort to bring this to this point. Take from it what you will.


    Now my two cents:

    Cast your eyes back at my cylinder head picture in the first post - 138000 miles with 6 Oil change services from 100K using Longlife 3. It has a good oil service history prior to me owning it.

    After swapping out my chains I continued to use Longlife 3 and swap it out every 5k. When I swapped out the chains at 138K I cleaned the inside of the rocker cover and both chain-cases - they were immaculate on reassembly.

    Recently I purchased an inexpensive endoscope to have some snooping about- what would my cylinder head look like after a further 45K and 9 oil changes... I was hoping for good things! Well thankfully the chain cases were still utterly clean as whistles but sadly the cylinder head was still manky black which is not a resounding testament to the cleaning abilities of Longlife 3. This tromped me to take stock of what I had been reading and really what harm could come if I swapped to an oil recommended in the 'What Oil?' thread and backed up with copious used oil sample analysis?

    So 1700 miles ago I dropped the old LL3 Oil immediately after a flush using a typical UK off the shelf product. I then switched to a recommended oil and after 1700 miles of use it was becoming noticeably darker - at this stage I used the recommended sludge remover which came out pretty damn manky and very dark. Prior to performing the flush the oil was already much darker than the Longlife Oil would have been at that mileage but certainly not manky by any means. I then dropped in some new oil and a new filter. That was about 300 miles ago. So I had a peek at the weekend via the oil filler and the endoscope - whilst its still rather dark in there the oil and flush certainly seems to have had some positive effect and there are lots of glimmers of silver and honey. I've yet to run the specified cleaning additive of which I have a couple of tins but I will be keeping stock with regular checks of the head using the endoscope.

    One last point - my 3.2 has never run so quiet and smooth as it does at the moment and always I have had chain noise (even after swapping out full new chains, tensioners, sprockets etc.) - very gentle noise but nonetheless certainly always there. However on a cold start now - no chain noise, no guide noise... simply injectors ticking away and noisy FEAD accessories. Every day I start the engine, get out, have a listen and then stick my ear to the passenger side wheelarch and think well maybe today it will be back... absolutely nothing! It's said on the german forums that a good 3.2 has zero chain noise and there are before and after videos posted on the a3quattro.de page. I always thought this was a bit of a stretch (no pun intended) but I'm now beginning to think otherwise.
     
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  12. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    A few points.
    Why were those 200 chains replaced?

    You talk about the oil pressure on MK4 and MK5 engines, I take it you mean AQN/BDE/BHE/BFH (and other EU3 engines) and BDB EU4 engines? With later being the MK5 BUB EU5 engine?
    Oil pumps. With those of us that run these engines turbo charged, an in my case I tap filtered oil pressure from the filter housing, how does this exceess potential pressure affect such an engine with an extra consumer, i.e the CHRA of the turbo?

    From the 200 chains sent to the OEM chain supplier (reason not stated), are those chains from a range of engines that have carryover parts?
    AQN and other V5 codes, BDE and other V6 codes, BFH,BHE, and other EU3 3.2 engines, BDB EU4 and BUB EU5.

    At least 9 years of VR mulitvalve engines. The A3 8P, which that forum is based on was introducded with an EU4 BDB. So are we capturing the entire mulitvalve twin VVT VR engine range with these postings?
     
  13. G60Dub

    G60Dub Forum Member

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    Valid questions for sure Adlai but I'm not sure if I am in a position to actually answer any of them given all I have done is read and paraphrase hundreds of pages of a3quattro.de. However they are relevant and valid in any case so I'll put them to one of the chain document authors - They seem a very good bunch but I'm not sure just how good my contacts English is so may need to get my Mrs to step in if a language barrier becomes apparent.

    Again to paraphrase - all chains and timing chain components including tensioners, sprockets and VVT Variators from vehicles deemed to be requiring chain replacement were sent to the chain document authors, at their request. I assume to collect components in an effort to attempt to identify a common cause. How many of the sets are spread between different base engines, private replacements and dealer replacements I do not know.

    It seems many people have chimed in with 'chain issues' across various 3.2 and 3.6 platforms across many models - It doesn't take a leap of the imagination to perhaps incorrectly jump to the conclusion that its purely related to shortcomings in the factory specified oil and service intervals hence not attributable to the design and function of the mechanical parts. However that's not exactly empirical data therefore it's not sufficient as a base to arrive at any firm conclusions hence I'll forward a link to your questions and see if we can get a bit more clarity.
     
  14. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    I was reading pistonheads and one owner of an 8P A3 V6 who sufferred from the problem linked to that document, in their response to Audi. That was 2013.

    The panic starts when the MIL is on and the fault is traced to "'Cam / Engine speed correlation error on cam sensor 2" or P1347.
    This has happened on engines with mileage as low as 80k miles when the cars had some worth and still new.
    80k miles is not the life of the engine it was argued in some cases.

    Those with 8P A3s where the first to highlight the issue. I also suspect this was related to the BDB engine, the variable oil service schedule and the manufactorue choice to use a specific chain supplier.

    It is also believed in the aftermarket tuning world, some of the oil pump drive gears from a certain batch oloder engine can wear, leading to loss of oil pump drive. Some of these gears are sometimes sold in chain kits. The gear seemed to have been superceeded to an "066" (5 cylinder) part.
    I understand the use of the old 12v drive (021) is perferred as it is the same and did not suffer that failure. The gear was later superceeded I understand. I have never tracked down which year was affected yet and why this failure occured, but changed this on my 3.2T project (8N TT BHE) with a new VW part as a matter course.
    No reports of issues with the chain in an EU3 BHE or BFH engine. Most require replancement anyway by now and many independants can handle this operation, by removing front end and de gassing the AC, taking both engine and gearbox out, splitting, removing the timing covers and getting on with it.

    I use "FEBI" chain kits on engines like these as they are OEM parts usually, with the logos ground out!

    One of the reasons I have not seen a lot of what the A3 8P german lot where going about, is because BDB engines are not really favorued by the aftermarket for a number of reasons.
    Being older engines usually a bit of miles, most are, out of warrently and due for timing chain replacement anyway as well as clutch and DMF! Most do not and the car gets broken for parts.

    Many factors can influence things gone wrong on a production batch. Also you have folks joining the bandwagon claiming this problem was seen with other engines, creating noise to the real issue.
     
  15. mk3f.t.w. New Member

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    Hello. Thanks for sharing all this great info. I tried the english pdf but the link does not seem to currently work.
     
  16. G60Dub

    G60Dub Forum Member

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    Sorry for the delay in replying - I've just tried the link and it downloads fine. Perhaps there is a post limit that you must reach before you can download documents? Admins feel free to chime in.
     
  17. rubjonny

    rubjonny Administrator Admin

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    yes for alternate file types you need to have a few more posts on the forum before it will let you download the files, I believe the threshold is 50 where your profile title will change from 'new user' to 'forum member'
     

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