I just did it to my own corsa with a hot engine and nothing happend My engine is clean unlije those morons who try to scare you! Great job ex castrol engineer
Well, the engine is HOT, because of that you could crack the engine block, warp different components, thats alot of water pressuse and water could enter inside the conector housings,inside the fuse box, etc.. just read the manual, it sais NOT to pressure wash the engine, and especially WHEN IS HOT!!