Hose engine
 

Any thing under hood have to be covered if i want to rinse out engine compartment?

some i5,3.7 plug seals leak . water gets in at seal or thru the mounting bolt, to the plug, could be big headache!
plug rust?, stick?
i would not spray

I wouldn't use the car wash sprayer on full blast that might screw something up

On my Alpha I have a plastic engine cover that I leave on. I've never really looked under the hood of the I5's too much, so I'm not sure.

I would say if you have an engine cover leave it on. Also don't use high pressure water, and keep the water away from your PCM. On mine its on the passenger side near the firewall.

Wet everything down and then use some elbow grease, that's probably the safest way.

I usually spray everything down with simple green and let it sit for a few minutes before rinsing. Use discretion, I don't simple green my belts or pulleys, or anything with a rubber seal. I usually just spray it on the underside of the hood, and around any really grimy areas.

My biggest fear with the simple green is degreasing the bearings in my pulleys so that's why I keep it away from there. Some people may say its not paint safe, but I've never had an issue with it inside the engine bay, it works wonders in the wheel wells though.

pulleys are prob pretty well sealed,they last forever with rain coming thru the rad, but i still wont spray xcpt maybe a mist bottle,,,aint worth the risk. a choice of soft brushes can help,,,if u really must mess with it. im scared of those hidden plugs, cant tell till the damage is done