How many miles were on yours that it had worn valve guides? When you say you assume the valvetrain was making a ton of noise
You know, interesting thing about this (long digression ahead):
From the DAY I first chipped the car (i bought it new) at round 20k miles it had problems making timing. I thought it was the tune, nothing more.
then i got AWE stage 3 at around 40k... and had TONS of issues. spent months with garrett et al who would try to fix it... this was back in the day before
anybody was self tuning. I got frustrated because my car never made power compared to other cars with mostly the same setup. It would do fine on race gas, just not 91oct.
I got so frustrated I was like, shit, i know the issues, i know what timing/afr/boost i want, i just need to figure out how to do it myself (because GIAC completely failed to get me anywhere close to what I knew should work). But obviously, there was literally NO publicly available information on anything. Googling for "KFMIRL" resulted in 0 hits. ZERO. When was the last time you got zero hits on a search?
So. timing/afr/boost. How hard could it be? 5 years later, and a shitton of work put into it, and i had a rough outline of the map locations and a rudimentary understanding of ME7.
I put it all the the s4 wiki, and soon after, tony started this site
But with all that, my car would still not make timing. So I thought, fuck maybe it's me. Maybe i'm still clueless and im missing something. So i start to tune a few other friends cars. Suddenly, their car is making more power than me. So now im like WTF! I figured i'd lower the compression, and at worst, ill get close to what I was seeing on other cars. Heads off. While they're out, I have them checked....
So i'm thinking, something bad happened either very early in the life of the car, or Hans was drunk when he assembled my heads.
So the theory is that the additional valve train noise may have been tricking the ECU into thinking i had knock when I did not... or.. something. No clue.