80V6 Engine Rebuild

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  • S2central.net
    Retired OG Mod
    • Jul 2003
    • 16590
    • Country: Northern Ireland

    #1

    80V6 Engine Rebuild

    Sorry its not an S2 project thread for me to kick off the new year but such is life. There isn't much said about these AAH engines (V6 2.8 liter 12V) on this forum so think of it as education... Though maybe better to move this into other sub forum.

    I have lots of pics to post - probably on a website somewhere easier than umpteen uploads here, but I have root caused the demise of the timing belt on this motor that has put me off the road for so many weeks... work, family and chrimbo somewhat took priority of my time so progress has been slow going.

    The timing belt tensioner uses a pulley that has the belt surface comprised of two halfs - one inner, one outer - welded to the bearing. On dismantling the engine I found that the welds on the outer surface had failed - causing the belt to only be partially supported but the shards of broken metal from the failed pulley caused the belt to be sliced longitudionally where it its remains then did several laps of the crankshaft pulley and of course it jumped some teeth and promptly stopped.

    Looks like a few gently bent valves are the only major drama, BUT - there is always a but. This timing belt was renewed before I got the car, but some witless person decided to 'save' 30 quid by not renewing the tensioner - maybe good economy for them, but not for me... Opening the engine saw evidence of some engine neglect by way of lots of old oily residue (I call it "glar") that you get from not changing oil often enough. Me being me cannot bring myself to put an engine back together in this state so it needs a proper checkover before committing to big spend on parts.

    Having bought the car for ~800 quid then spent best part of 400 to get it thru MOT I had to dig deep in my thinking as to whether to keep it... Doing a proper engine refresh is going to cost more money than another 'clunker' runaround - assuming I could find something suitable and reliable.

    So given this car is now largely a known entity - sure it has its faults but the car is rare, practical and fun to drive... I really missed getting out in the snow this year

    I've decided to do a proper engine rebuild to give this car a properly good motor that I can trust... Well if it blows up again at least it will be my fault

    The other reason I decided to do it, is that its been quite a few years since I did a full engine build and this will refresh my skills for something more fruity in the S2 department - hopefully by next xmas...

    The block is completely dismantled now - took two good degunges to rid it of glar and will need another clean after honing before its ready for paint. The sump was horrendous.

    On a technical note - it was interesting to see how a V6 rolls internally - these have cross-bolted central main bearings as well which I didn't expect.

    All the main bearings look to be in good condition, but a couple of the conrod bearings are showing some signs of stress - almost certainly from kak oil... The crank itself seems perfect so I think fresh bearings are all I need.

    Jees - sorry for such a long rambling thread with no real beef, but thats the plot outlined at least. As I said - I have loads of photos for my own benefit to recall how to put the beast back together (was no mean feat removing it by myself either - I won't be breaking Tonks records for sure) but I'll post some highlights here in due course.

    Paul
    Paul Nugent
    Webmaster http://S2central.net
    Administrator http://S2forum.com

    1994 S2 Coupe ABY - aka Project Lazarus
    2001 A6 allroad 2.5TDi - family tank
    2003 S4 Avant 4.2 V8 - daily burble

    Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

    There are only 10 kinds of people that understand binary - those that do, and those that don't
  • Flat on my back
    S2Forum Fiend
    • Jan 2007
    • 2449
    • Country: United Kingdom

    #2
    .

    Heavy lumps aren't they...welcome to the 'one man band'...
    Carlos.

    On the look out for less bits for my s2 saloon project. Now supporting myself by shooting for my food. www.airgunforum.co.uk

    Comment

    • Rusty
      Super Moderator
      • Jun 2004
      • 18953
      • Country: United Kingdom

      #3
      Check out Tonks's threadon christmas fun, there's some inspiration in there in the form of a white v6 80q
      Cheers'en, AndyC
      1994 ABY Coupe - Projekt Alpinweiss

      Comment

      • Skull
        S2Forum Possessed
        • Mar 2004
        • 3506
        • Country: Slovenia

        #4
        what about buying another engine? maybe from an audi 100, a6, a8... they are very cheap here, a friend bought one for 80€...
        Audi Quattro WR

        Comment

        • S2central.net
          Retired OG Mod
          • Jul 2003
          • 16590
          • Country: Northern Ireland

          #5
          @Carlos - damn right they heavy - ridiculously so - even just the bottom end on its own. I almost gave myself a hernia lugging that round the garage after I took it off the engine stand.

          @Rusty - always admiring Tonk's speedy spanner work !
          Paul Nugent
          Webmaster http://S2central.net
          Administrator http://S2forum.com

          1994 S2 Coupe ABY - aka Project Lazarus
          2001 A6 allroad 2.5TDi - family tank
          2003 S4 Avant 4.2 V8 - daily burble

          Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

          There are only 10 kinds of people that understand binary - those that do, and those that don't

          Comment

          • S2central.net
            Retired OG Mod
            • Jul 2003
            • 16590
            • Country: Northern Ireland

            #6
            @skull - I did think of that and I might yet if I find one for that sort of money locally as a way to get on the road quicker, BUT the downside is its another unknown entity and I'd have to swap it all again when the rebuild is finished. Cheapest I saw on ebay UK was circa 400 Euros... and yes the thought of 30V (ACK iirc) upgrade was considered too - just too much of a project for me now though having to source a different loom, ECU and removal of dash to fit that properly.

            Planning to keep this old car as a reliable old 4-door stealth mobile so it'll cost me more short term to get it rebuilt nice, then hopefully I can have mostly trouble free motoring with it... Thats the plan at least.
            Paul Nugent
            Webmaster http://S2central.net
            Administrator http://S2forum.com

            1994 S2 Coupe ABY - aka Project Lazarus
            2001 A6 allroad 2.5TDi - family tank
            2003 S4 Avant 4.2 V8 - daily burble

            Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

            There are only 10 kinds of people that understand binary - those that do, and those that don't

            Comment

            • V6quattro
              S2Forum Maniac
              • Sep 2008
              • 949
              • Country: Netherlands

              #7
              Nice take a look at my post on a dutch forum. And do you have the special timing tools?

              Ik ga deze en volgende week wat aandacht aan mijn 80 besteden. To-do lijstje + Koppakkingen vervangen + gereviseerde koppen ivm olie lekkage. + Overdruk klepjes in kop vervangen. + Olie trugstroom klep
              1360kg/600Whp Avant 0-200km/h 9sec

              Comment

              • S2central.net
                Retired OG Mod
                • Jul 2003
                • 16590
                • Country: Northern Ireland

                #8
                I have the V6 crank lock tool (same as AKE TDi lump) but I don't have the camshaft tools yet... Need to get into garage tonight for some dimensional checks on bearing journals before I start spending money - gonna be into four figures to do this properly. I must be insane.
                Paul Nugent
                Webmaster http://S2central.net
                Administrator http://S2forum.com

                1994 S2 Coupe ABY - aka Project Lazarus
                2001 A6 allroad 2.5TDi - family tank
                2003 S4 Avant 4.2 V8 - daily burble

                Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                There are only 10 kinds of people that understand binary - those that do, and those that don't

                Comment

                • V6quattro
                  S2Forum Maniac
                  • Sep 2008
                  • 949
                  • Country: Netherlands

                  #9
                  If you need sum info or measurements i have all the workshop manuals and crack/cam shaft locking tools.
                  And i really like the horizontal bolds in the main-caps. Even the 20VT dont have thees.
                  1360kg/600Whp Avant 0-200km/h 9sec

                  Comment

                  • Error404
                    Super Moderator
                    • Mar 2007
                    • 19789
                    • Country: United Kingdom

                    #10
                    that is exacltly what happened to my V6 cq Paul, tensioner disintegrated and killed the engine. I opted for the easier optuion of sticking another lump in so i admire your dedication to the cause

                    Looking forward to seeing some pics of the build up
                    Panthero Coupé quattro 20vt
                    Indigo ABY coupé
                    Imola B6 S4 Avant

                    Comment

                    • S2central.net
                      Retired OG Mod
                      • Jul 2003
                      • 16590
                      • Country: Northern Ireland

                      #11
                      @v6quattro - do you have those manuals in paper or PDF format ?

                      I am using 'elsie' of course which I hate with a passion - I much prefer paper pages to flick thru.

                      @Error - mine is the 1st generation of AAH of course... There were two variants after that - you'd have to hope that AUdi improved this tensioner on the later versions but I haven't checked the family album. The later versions also have some modifications to the oil system to allow running with lighter valve gear - which would be nice (if expensive)... Dunno if Gen1 block can be modified to run them though - I don't want to be the guinea pig on that.
                      Paul Nugent
                      Webmaster http://S2central.net
                      Administrator http://S2forum.com

                      1994 S2 Coupe ABY - aka Project Lazarus
                      2001 A6 allroad 2.5TDi - family tank
                      2003 S4 Avant 4.2 V8 - daily burble

                      Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                      There are only 10 kinds of people that understand binary - those that do, and those that don't

                      Comment

                      • S2central.net
                        Retired OG Mod
                        • Jul 2003
                        • 16590
                        • Country: Northern Ireland

                        #12
                        Some pics then...

                        1 - the half width belt
                        2 - some 'glar' in one of the heads - yuck
                        3 - part of the failed pulley
                        Attached Files
                        Paul Nugent
                        Webmaster http://S2central.net
                        Administrator http://S2forum.com

                        1994 S2 Coupe ABY - aka Project Lazarus
                        2001 A6 allroad 2.5TDi - family tank
                        2003 S4 Avant 4.2 V8 - daily burble

                        Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                        There are only 10 kinds of people that understand binary - those that do, and those that don't

                        Comment

                        • S2central.net
                          Retired OG Mod
                          • Jul 2003
                          • 16590
                          • Country: Northern Ireland

                          #13
                          1 - stripdown started... was originally going to just do the head gaskets and new timing gear until I saw just how sweaty and unloved this engine was. Also the removal of heads, IM and all the fuel, water and stuff made for easier access to bellhousing

                          2 - very easy to run out of floor space with this job
                          Attached Files
                          Paul Nugent
                          Webmaster http://S2central.net
                          Administrator http://S2forum.com

                          1994 S2 Coupe ABY - aka Project Lazarus
                          2001 A6 allroad 2.5TDi - family tank
                          2003 S4 Avant 4.2 V8 - daily burble

                          Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                          There are only 10 kinds of people that understand binary - those that do, and those that don't

                          Comment

                          • S2central.net
                            Retired OG Mod
                            • Jul 2003
                            • 16590
                            • Country: Northern Ireland

                            #14
                            1 - almost ready for the crane

                            2 - ahh there it is... blooming awkward too without lifting points on the head. D'oh

                            3 - and enjoy the signs of sweaty rear crank seal and/or gearbox input seal added to a bit of spilt coolant in the bellhousing
                            Attached Files
                            Paul Nugent
                            Webmaster http://S2central.net
                            Administrator http://S2forum.com

                            1994 S2 Coupe ABY - aka Project Lazarus
                            2001 A6 allroad 2.5TDi - family tank
                            2003 S4 Avant 4.2 V8 - daily burble

                            Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                            There are only 10 kinds of people that understand binary - those that do, and those that don't

                            Comment

                            • S2central.net
                              Retired OG Mod
                              • Jul 2003
                              • 16590
                              • Country: Northern Ireland

                              #15
                              1 - consider this the engine bay 'before' pic ;-)

                              2 - engine installed onto stand for subsequent disassembly and initial delousing
                              Attached Files
                              Paul Nugent
                              Webmaster http://S2central.net
                              Administrator http://S2forum.com

                              1994 S2 Coupe ABY - aka Project Lazarus
                              2001 A6 allroad 2.5TDi - family tank
                              2003 S4 Avant 4.2 V8 - daily burble

                              Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                              There are only 10 kinds of people that understand binary - those that do, and those that don't

                              Comment

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