I've always been afraid to detail engines...theres so many mixed opinions on what is safe...
1) Some say warm the engine for 5 mins, then turn off, then no need to cover anything, then hose away and degreaser, agitate and rinse, then turn on engine to let it dry
2) Some say make sure engine is cold (basically do it first thing in morning), hose everything, degreaser, agitate, rinse, and air dry
3) some say cover some parts...
which is it? and what parts do you need to cover? is it safe to just hose it down without covering anything? the only part of detailing that I am afraid of.