what can I and what can I not power wash? engine? underneath? grill? everything?

 

I didnt everything and just used the plain old hose on the engine with some simple green after covering vital electronics with bags.

 

I would stay away from power washing your engine bay, you don't want to knock a wire loose and kill yourself trying to find the problem. Just use some engine degreaser and hit it with a garden hose.
After covering all your electronics of course!

 

Whoops. I wouldn't use a power washer, but I sprayed gunk twice and hosed it off with out covering anything. I just made sure to avoid the distru and fusebox.

 

underneath?

 

Two hoses and ten minutes time and everything was clean. The frame has some thin film on it, but two minutes with a sponge, and it'll be gone.

 

i powerwashed my truck at work, ofcoarse with the truck running, no porblems, but then again i only did the oil pan area

 

i powerwash almost everything but the engine just set it so its a wide fan type spray pattern

 

I just cleaned up everything after the Yankee Hill run and I just used my garden hose and some Simple Green and avoided high pressure spray toward the electrical goodies. My engine is pretty much grease free so I didn't need much else and then when it's dry I spray tire dressing over everything for the "new" look.