My engine is a bit dirtier than that. I specifically instructed the dealer to no more than rinse the salt off the body from my test drive and vacuum the seats and carpet, because dealers always wash new cars and trucks with bricks.
Irritatingly, they DID wash it, and so I'll be spending a Saturday going over the truck with a DA to fix their damage. It's wild to me that anyone *wants* the dealer to clean it... hell no! I've already compounded out a few deeper scratches, and waiting for the final freeze here in Michigan to come and go so I can turn on my irrigation circuit, which is what my front spigot is connected to. Then I can wash, iron decon, clay mitt, and polish in prep for coating. Bought the truck two month ago and annoyingly the weather forecast still shows a couple overnight lows under 32F.
Washing the engine on a new vehicle is easy, no need to think far into it. You might be able to simply rinse it down with a garden hose and blow dry to get all the dust out. I would have already done that myself if I had a hose right now instead of car wash pressure washers.
If it's more just dust, then spray your favorite APC (I use Meguiar's Professional series APC concentrate and diluted in a spray bottle) or degreaser (10:1 dilution for lightly soiled areas, 4:1 for older engines with grease and grime), scrub with a wheel brush (use a long brush intended for wheel barrels to get deeper areas) and rinse it down. Blow dry the bigger pools of water and then air dry. If it suits you, apply a dressing for that "factory fresh" look.
The truck is far too new to need a steamer. Don't use a pressure washer. Don't spray into the airbox. Don't spray directly into connectors/alternator.