I've also heard of using ATF to free up sticky hydraulic lifters, and it's approximately the viscosity of 10 weight oil, but I'm a little reluctant to run something in an engine with the friction enhancers that make automatic transmission clutches grab and hold. ATF cools and lubricates as well as developing enough pressure to make clutches and bands do their thing, but I prefer something a little different for engine cleaning.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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