I do it to all 3 of my diesels all the time. Not once have I had a problem. There is a proper and improper way of doing it. If you do it wrong, your going to have problems.

Use Gunk and spray it onto the engine, let it soak for a couple minutes, then use the soap, then rinse. Make sure you rinse the paint area as well.

Try not to hold the hose too too close to certain components like electical wires, etc. Start the car and drive around for a while to dry it off and you will be fine.