This seems to be a prevailing concept on washing the engine...."I was washing my engine while it was running". This is a no no! The right way to do this is to let the engine cool off first prior to spray the engine chemical cleaner or just plain washing with water. If the engine block is extremely hot & you spray it with tap water, there is good potential of cracking your engine block. Avoid doing this misconception that the cleaning solution will work better with a hotter temperature. Instead let the engine cool off first, spray it with the cleaning solution and let it soak in for 5 to 10 minutes. Then start the engine and rinse with water but do so quickly before engine gets to it's normal operating temperature. Don't spend more than 5 minutes rinsing off the engine. Then rinse around the engine like the wheel covers, the headlight sections, radiator etc. Avoid spraying into the engine after the first 4 to 5 minutes.