fsi / carbon buildup

[thejimrose]

rumor is that the euro audis [not m/a yet] are using upstream injectors
[intake] to wash the backs of the valves to prevent / minimize carbon
buildup. read any rs4 forum about it, the pictures are a horrorshow. guys
rolling in with the ports 50% clogged and putting down 200hp. agreed that
it's a 40k service check / job. i think most shops are doing it for a few
100$. it's not a nightmare, just another component to the vag ownership
'character'. trade your cam follower checks / replacements with decarbon
treatments.

also it sounds like guys running pcv deletes, catch cans, and frequent
seafoaming in the intake still doesn't prevent the carbon buildup. i know
nothing of chemistry but it makes sense that you need some fuel to act as a
solvent to prevent carbon from forming when the engine is hot, once it
forms/hardens during the drive cycle it's probably mostly there to stay,
until it's forcibly removed a la media blasting and dental picks.

no such issues on my sti. of course the ride quality is like being in a
metal trashcan full of hammers rolled down a hill.