I've only been a driver for going on 3 years now and have never cleaned under the hood of a vehicle. Untill i recently purchased my new truck and saw how clean they Could be it never crossed my mind. This may be the ultranoob thread on the site but i really dont care- how do you safely clean under the hood? Just spray it off would be the obvious guess but i dont want to fek anything up.

 

I've always used Gumout's Engine Brite EB-1. Used it on every vehicle I've ever owned. Three cans the first time I did my truck, it was filthy, don't think it had ever been cleaned. Once it's clean it's a lot easier to keep it that way. I do this at a coin-op carwash. Take care about your fenders & hood, don't let this stuff stay there long, it's hell on paint & wax. I take off the aircleaner, clean it separately, and tape a sheet of plastic trashbag over the carb. Spray it on a cool engine, use a parts brush, rags, and "elbow grease" on the worst spots. Let it sit 5 or 10 minutes. Hose it off, but go easy on the water, just enough to rinse the chemical off. Get the rest with rags & such. Never had a problem with the distributor or any other electronics, but you can spray WD-40 on it before to repel water or after to displace it. Use ArmorAll on hoses, plastic & rubber parts under the hood, belt dressing on your belts, and lube all the hinges & latches. I have heard some horror stories about steamcleaning, but I've never tried it.

The best thing is the smell of an engine after it's cleaned this way...almost like new-car smell. I love a clean engine bay. And now if anything's leaking, I'll see it.

 

Cover everything electric up with waterproof something. cover every hole, slot and other place for water to get in, spray simple green on everything, and rinse it off.

I have done that on engines for a long time, with no problem what so ever.

 

Its time to break out the pressure washer!

 

If the engine bay isn't too dirty (none of mine are), you can use Greased Lightning. I usually dilute with water before I apply it. This stuff works great for cleaning just about anything. Just spray on, let it soak, then rinse. I also use it to clean my tires.

 

I picked this tip up from somewhere else on the FTE forum and it works really well. (Since the search feature is down I can't link to it.) This works best with an engine that it not seriously dirty, otherwise use the heavy duty stuff first. Warm the engine and then spray everything underhood generously with Armour-All. Close the hood and let it soak overnight. The next day spray off with a light spray from the garden hose and allow to dry. The results will just amaze you- at least it did me. (Armour-All has some mild detergent properties and the residual silicone coating leaves all the hoses, metal and plastic looking spanking brand new.)