Originally Posted By: G-MAN
Look at this build up on the intake valves of an Audi DI engine:
That photo looks like it is from a very low mileage car. Here are some with higher mileage:
Here are some treatment methods copied from my post in JAGs bmw thread
Here is a video of the BG induction service that Crew219 found on VW vortex
http://www.vimeo.com/3989681
Also, here are the techniques I know of to deal with valve deposits (from the audi/Mikeinaustin thread):
Some very easy/low cost preventative options that can help but will not solve the DI valve deposit problems:
1) Use a low volatility and good cleaning oil (cost: additional $5-$10 per oil change)
2) Seafoam, lubro moly valve cleaner, water, etc. through the intake at every oil change (cost: $3.50-$10)
3) Regular italian tuneups (cost: gas)
4) Catch can (all kinds of flavors out there) (cost: $30-$300)
5) Fuel injector cleaner in the gas to deal with fuel injector deposits (will not help with intake valve or intake deposits) (cost:$5-$10)
More difficult/expensive "helping but not solving options"
6) BG induction service or similar (cost: $135-$250?)
7) water/meth injection (cost: ???)
8) remove intake and clean valves every 50k or so (cost: ????)
Some one-time-fix-the-problem options:
1) bypass pcv and route to exhaust (search for saaber2 thread "bypassing pcv") (cost $125-$175)
2) Run a catch can that vents to atmosphere ((may increase build up acids in oil due to lack of vacuum in evacuating crankcase gasses (but that is unknown)?)? may have smell or freezing issues?) (cost: $300?)
3) Run a "down tube" or "road tube" that vents to atmosphere ((may increase build up acids in oil due to lack of vacuum in evacuating crankcase gasses (but that is unknown)?) (cost: $25 -$50)