you can use gunk citrus, or regular gunk for a oily engine. I spray the cleaner on a very warm engine, (a 2-3 mile journey) and all the under-hood components. Then take a water hose on a spray setting and just spray enough to remove the cleaner and grime. I would not advise to spray large amounts of water continually on engine. the trick is to let the engine heat dissipate the moisture before starting up.