At lexus right now we have been doing top engine cleans on the 3gr/4gr. Massive campaign going on. They have severe carbon build ups on valves do to faulty rings, its a band aid fix until they can get the entire motor rebuilt at a later date. Pull of the plenum and lower intake mani and all the plugs. We pour this nasty shit into each intake port, an exact amount. We then turn the over by hand several rotations, then cover up all the spark plug holes with rags and crank the motor over with the starter.
Put it all back together, fire it up and it smokes for a good long time, just like seafoam. The difference being the precautions we take to not let it hydro lock the motor and have it all pool up in the engine like gadget said, and blow a rod through the block.
It will usually keep the car running a lot smoother for few months, until it builds up again. POS engines...:thumbdown:
