i use a combination of autoglym engine cleaner, gunk spray, gunk brush on, and wd40, i use cloths, wire brushes, wire brushes on a drill (these for the first ever clean) and paint brushes.
I then rinse the safe parts with clean water using a watering can, then run engine to dry, at this point, the gearbox and some other parts go very dry/white looking (aluminium bits) and in my opinion look crap so i spray the whole lot again with wd40 again and leave to dry naturally. and then on the rubber and plastic bits i use engine detailer to give a nice shine, if i run out of that i just spray wd40 on those bits too but wipe it after iv sprayed.
end up with summart like this, although i spent many hours hand polishing and sanding this engine in my swift GTI
gonna do the same to my mk 3 GTI golf daily driver next

