Need to clean the dirt off my engine is it safe to just wash it with a hose?

 

I hose mine out every now and then. I make sure to cover the alternator, battery, airbox intake and fuse box. I usually use Walmart sacks to do that. I just make sure to not drowned everything.

 

No problems I would cover the alternator but not worry about anything else. You may get a build up of condensation in some of the connections so I would afterward clean it with contact cleaner and use die-electric grease. Be careful as there are two types of contact cleaner and not all are safe for plastics and paint. I would also just use a hose not a power washer they can bend the fins on a radiator and push water into unwanted areas.