engine bay cleaner/ engine cleaner from halfrauds, a good stiff brush, and a pressure washer.
wrap all electrics up i.e.altenator, ecu, afm, and isv and dont forget dizzi and leads! wrap them in plastic bags, secure with ducktape.
give the whole bay and engione a good spraying with cleaner, leave for 5 - 10 mins, scrub it all with brush, clean with pressure washer.
reapeat however many times you feel nessesary.
(i advise doing it on the grass verge outside your house, or somewhre that isnt on your dads brand new driveway.)
then off with all the plastics, make sure its reletivly dry, and fire her up, leave running for a while to dry the bay out, and hey presto, show car clean engine bay.
another trick is using the morrisons or alike jet washer. buy the code, type it into the machine after prepping the car on the forecourt.
then when the time runs out, push the car into the second bay(if there is one) and type in the same code again, and 9 times outta 10 it works.
hope this helps...
rob