Just to add to it...if you get the chance a few days ahead of time, soak the engine down on the outside with some Dawn dishsoap. Then when you go at it with the power wash, that stuff will really help cut the grease and crud. I also don't like a dirty engine and learned the hard way about keeping them clean. When I had my semi(KW) and it went to the shop the first time, when I paid the bill there was a charge for $75. When I asked about it they explained to me that they put a lackey on it with a steamer to clean it up before the mechanic took over. I figured after that it was a lot cheaper for me to buy my own powerwasher and keep it clean. Then when it developed a leak, I could find it and stay ahead of the grime under the hood.
