Re: Any one tried the hydro cleaning of carbon for engine?
What is more important IMHO, is the below little note by Team-BHP.
That decarbonising can cause a slight loss of power or increased oil consumption is well-documented for older engines. This is usually attributed to the breaking down of the oil seal between piston edge and cylinder bore, by the removal of the ring of carbon that had formed on the piston edge. However, in time a new oil-seal may form and the compression would therefore improve.
New generation engines do not form so much carbon during combustion. Removing whatever little has formed to compensate for cylinder bore wear, MAY leave you with leaky pistons after decarbonising.
Flushing can cause oil seals in the lower half of the engine (such as big-end bearing seal) to leak - decarbonising can do the same to the fuel pump.