First time posting but have been reading other posts for about a year or two and I'm writing this because I have actually fixed the issue finally after 6-8 months of research and trial and errors to get it fixed but just in case anyone ever runs into this issue here's the break down start to finish.
Background: Bought a 2000 Laser red S4 200K+ miles on chassis with blown turbo's. When I pulled the turbo's the driver side had a "Lag Bolt" sitting inside it. I never drove the car so I never knew how the engine ran before i Did the fresh engine rebuild with all new valve seals and piston rings and put in 2.8 intake cams, forged rods. Engine has new K24 turbo's, new SRM side mounts AMD stage3+ clutch kit. Running a no name Nefmoto stage 2 tune and stock injectors for now. Have all the new parts to make it go fast later but wanted to get it running on stockish set up first.
Symptoms: First start up last year after rebuild it ran great. Only issue was i swapped around a waste gate line which did over boost the turbo's and it spiked to like 40+psi, and nothing was really damaged at first thought. But then I would start getting misfires in just bank 1 but on all 3 cylinders at idle only. I could be driving it and no misfires or I could pre load the engine with the clutch and no misfires. But at dead idle it would misfire and it was like 30+ on cylinder 1 and like 80+ on cylinder 2 and 50+ on cylinder 3. Swapped coils and ICM's and injectors around, nothing followed. Replaced with new 2.0 coil upgrade, still nothing changed. Re flashed the ECU back to stock just to make sure it wasn't a bad tune on the car and nothing changed. Checked timing a million times and it all lined up. 16 links in chain and tensioner moved up and down when cranking engine by hand. Did compression test and found bank 1 lower then normal for a new build so pulled engine and replaced rings. Started it back up and less misfires but they were still present. I have had ZERO codes for cam issues or timing issues the entire time.
The Fix: Basically after running Vag-com and looking at block 93 (or 94 cant remember) but the cam phase block, bank 1 was at -11 and bank 2 would be -1 or zero. No matter what I did driving or idling bank 1 cam phase was always -11. After hours and days and months it came down to even though the tensioner was appearing to be working I figured id do what your not supposed to do and throw more money at an un known issue. I replaced the chain tensioner and BAM ZERO misfires!!!!!! I never had chain rattle noise I never had any sort of cam position codes nothing! but somehow the tensioner worked but worked just enough to keep the rattle from happening and keep the car from throwing any other codes to elude me to a bad tensioner. I have researched and researched and never found anyone with the same symptoms so I never really had anything to go off of. But it is fixed and driving the way it should be
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