I use a engine degreaser if the stuff is really caked on (only once /ubbthreads/images/graemlins/laugh.gif )
Then, to keep up with it, I use Simple Green. I usually use it concentrated, but since I bought a huge gallon of the stuff with sprayer, I'm going to try mixing it with water and see how it works cut down.
I use a gallon sprayer that was bought at wallyworld for around $10 or so; the type you spray weeds with.
I has enough power to get stuff off, but you can also aim it pretty well.
I also stay off the IDM, PCM and watch the ICP on the driver's side oil rail of the V, towards the front of the engine. The little guy is sticking up and if not careful, can get water in it.
I'll spray a mist over the engine and bay, then spray the cleaner and wait 10-15 minutes. I then rinse and she is done. I just bought a tile grout brush at Home Depot last night and I'll use that for the hard to get off stuff.
I'll have to try the pledge. That's a good idea.