Let the engine cool completely
Disconnect the battery
Cover sensitive electrical components, air intake, alternator, fuse box, and exposed wiring with plastic bags
Remove loose dirt and debris with a brush or compressed air
Apply a degreaser to dirty areas
Let the degreaser sit for a few minutes
Scrub stubborn grime with a soft brush
Wipe surfaces with a damp microfiber cloth
Rinse lightly with low-pressure water or a damp cloth
Avoid soaking components or using high-pressure spray
Remove all plastic covers from protected parts
Dry the engine bay thoroughly with clean towels and compressed air
Reconnect the battery
Start the engine and let it run briefly to help dry remaining moisture