Saw a couple of older threads here and thought I'd summarize them as I'll be tackling this job in the next couple of days.

0. Start with either a cold or slightly warm engine
1. Bag and tape major electrical components such as the ECU and COPs (some don't do this; most appear to)
2. Spray engine down with either dilute Simple Green, an all purpose auto cleaner or a specialized engine cleaner spray
3. Allow to dwell for 5-15 minutes
4. Agitate gently with soft brush or cloth to loosen crud
5. Hose down gently with the minimum amount of water that'll do the job
6. Repeat if necessary
7. Treat rubber and plastic with a rubber and plastic protector. Some use 303 Protectant

CAUTIONS:

• Full strength Simple Green may or may not etch aluminum
• Rewax painted areas of the engine compartment after washing it down with the degreaser
• The wrong rubber / plastic treatment may remain sticky and attract dirt/dust

Anything to add here? I think I accurately synthesized the posts I saw on this topic.

 

1) While spraying the engine cleaner, take extreme care not to get overspray on the cowling. Even if you are careful, after immediately after spraying the degreaser, wash the cowling with clean soaped 100% cotton rag; rinse with a light spray of water (so as to minimize the possibility of rinsing engine cleaner from the firewall).

2) Don't do what I did and spray the underside of the bonnet with engine cleaner. I later wiped aggressively with rag to remove grease, etc; I ENDED UP REMOVING SOME OF THE HYPER-BLUE PAINT ALONG WITH THE GRIME! (not one of my proudest moments as a MINI owner )

Before and after pics are in my Gallery...

 

I spray the underhood plastic and rubber with Griot's engine bay dressing after cleaning. Makes it look like new.

 

I shot my rubber stuff with Meguiar Hyperdressing diluted 3:1. Nice finish.

 

Wow, great! Thanks for the tips! Got any pics of the engine bay after detailing?