Liqui Moly intake valve cleaner
I was recently buying a bunch of Liqui Moly stuff (oil, cleaners of all types, etc) and I noticed a product called Einlassventilreiniger fur direktenspritzer. As far as I can tell from the German and the way it was translated to Russian, in English it would read "Intake Valve Cleaner for Direct Injection". Dackelone and perhaps others have mentioned another product they have called something like Drosselklappenreiniger which is a Throttle Valve Cleaner but has apparently been successfully used on our N54s to at least somewhat clean the intake valves. I have tried using it before but couldn't even get black smoke, which led me to believe that it wasn't working for me for whatever reason.
Now, I will of course agree that the best way to really clean your carbon buildup is by a proper mechanical method, i.e. walnut shell blasting or similar. However, given the price of the can I figured there is no harm in trying.
My issue is the following, the instructions are pretty wild:
Unscrew your spark plugs
Spray 25-50ml into each spark plug hole
Wait 6-12 hours
Crank engine without plugs using starter
Reinstall plugs and go
1) Does pouring that stuff in there seem safe and ok to everyone?
2) How does one crank the engine without plugs on an automatic? Can you just unplug the coils/plugs and press the start button or how does it work?
3) The can says the cranking gets rid of the solution and gunk. Doesn't that mean it ends up in the oil? Or is it meant to be thrown into the exhaust? Neither seem great.
4) As we know from carbon buildup cleaning DIYs some of the valves are open and some are closed at any given time. To me this seems that the solution would only help with the valves that are open and thus submerged in this liquid. What are your thoughts?