Additives

[Yaris Hilton]

Originally Posted by ka0sx

there is also a cleaner that will clean out your entire engine of carbon buildup better then techron or any of the popular brand cleaners, was designed to be clean for marine use, cant remember the name at the moment. It requires some knowhow though, You put it into the engine directly through a vacuumme line at about 3k rpm then when it drains the can you instantly shot of the engine and let it sit for about 30 - 60 minutes.
after this you are good to restart the engine, there will be lots of white smoke, dont worry your engine is fine it is just the product and carbon buildup exiting out the exhaust. After the procedure change your oil withing the next 100 miles.
once again this is the most intense and best method to get rid of the carbon buildup in the engine, but I wouldnt recomend it for any car with less then 150k miles on it, unless your car has been running rich and you are now failing smog for high NOx

Nothing new about that, it's a real throwback. Those carbon cleaning solvents, under numerous brand names, were popular in the old days before emission controls. Usual advice was to remove the air cleaner and pour it straight in while holding the throttle open to rev the engine, pouring the last bit in fast enough to kill the engine. After letting the warm engine sit with this stuff in it for a few minutes, you restarted the engine, revved it with the smoking, misfiring and backfiring till it smoothed out enough to drive, then took it out on the road to progressively run it up faster till it started missing, hold it till it smoothed out, then gun it up some more. Then you immediately changed the oil and the spark plugs, as the oil would be diluted with solvent and the plugs would have all kinds of gunk on them from the deposits loosened in the combustion chamber. Following that procedure will quickly overheat a catalytic converter and will set error codes in an ECU, and would not generally be recommended for modern cars. But it sure will get a lot of carbon buildup out of combustion chambers.