First off, a little background. I just bought the car from my dad, who's had it since 95. He's not the enthusiast type, so he's never abused it, never modified it, never looked under the hood. Always dealer serviced.
Anyway, I get it two months ago, and the engine is filthy. I'm usually not one to care how nice the engine looks -- but this thing is nasty to the point where it's not even fun to work on the engine. So after looking at all the methods of cleaning on the net, it's time to go at it.
Stock engine, before any cleaning:
1. Cover all openings. I did the air cleaner, turbo scoop thingy, spark plug cover vents, alternator, and battery terminals.
2. Tried Gunk Citrus Brite Engine Cleaner. NOT RECOMMENDED! Got rid of some of the caked-on dirt, but not even close to clean. The downside was it made the engine smell like a burned-down orange orchard! Every time I got out of the car I could smell it. Nasty stuff. Drove with that for a couple weeks.
2. Got a can of Gunk Foamy Engine Brite. Now this is the good stuff. Emptied the whole can on the engine, foaming up and coating everything I could get. Make sure to wipe the front fenders, wiper arms, headlights, and bumper with a wet paper towel, to get off any of the degreaser overspray.
3. Wait about 10-15 minutes, then hose the engine off with a garden hose and/or sprayer attachment. No pressure washing!
4. Broke out a spray bottle of Simple Green degreaser/cleaner and a toothbrush. Poured some into a cup, and diluted 1:1 with water. Then went to town for 2 hours, scrubbing each component, hose, and section of the engine bay, as far as the toothbrush would reach. Prepare for back pain. Spray off each section as you go, so the Simple Green doesn't dry on it. Some people have problems with aluminum being etched by it. No problems here with the diluted mix.
5. Hose everything off, remove the covers, and drive it around to dry all the components.
6. Armor-All Tire Foam. I put maybe 1/3 of the can on the engine. It coats it pretty quickly and shines like a mofo. After spraying it on, rub all the hoses and plastic pieces to evenly coat them. I waited overnight before driving, but I'd say you could hit the road immediately.
That's it! And the results are:
Hopefully this will be inspiration to put the time and elbow grease into cleaning the engine bay. It's worth it in the end
94 Supra TT
01 Viper ACR