try using a degreaser called Super clean, it comes in a purple spray bottle most auto part stores sell it I get mine at walmart by the gallon... warm up the engine for about 15 minutes to get it hot, shut off the eng spray the dirty areas and watch the grease just get eaten up LOL it turns a brownish color, BUTTTTTTTTT BE CAREFUL WHERE YOU SPRAY IT...dont get water on the mass airflow sensor!! just be careful where and what you spray or you`ll be back here posting why doesnt my engine start...dont start the eng right away after cleaning it , let it air dry for awhile..Good luck keep us informed on the outcome of the cleaning, with pics..