here is my .02...take some real degreaser...purple power or simple green something along those lines..get some hot water and ajax soap, get u some good hot soapy water out of that..have a brush, similiar to what u would wash a car with...spray degreaser on that whole engine bay..let it sit, then use the brush and wash the crap out of the bay..use a rag for the small nooks and crannies and it should come out way better. when u are finished with it like that..either use some quick detailer or soem easy wax/polish and wax/polish your engine bay.