Find a company that sells power washer cleaners for washing/degreasing machinery. I did that many years ago and found a product from a local supplier so that my dad could clean/power wash his farm equipment - combine, tractors, etc.
NOthing works better than steam cleaning. Find a place where you can rent a hot water machine and your good to go
I have always preferred rags, scrapers and elbow grease. Sometimes power spray just bounces off grease and dirt.
Yes, hot washers are the best!! I think we rented ours for like $80 a day. It's not a small machine, but it will roll into the bed of a pickup.
Simple green solution, spray it on let it soak, use a stiff plastic brush to scrub, then pressure wash. Repeat if needed.
If your doing this in your driveway at home I think engine degreaser is a SOY Byproduct now. Witch is (green) enviro safe. Not sure though.
Hit it good with the pressure washer first. Some have small containers for soap. Simple green worked alright and seemed safe to use. Gunk engine degreaser might also help with the rough spots. I did mine out in the hot sun. Hooking up to some hot water will help also. Chances are you are gonna have to get the small putty knife out and scrape away. Have fun
Spray it down with HEAVY DUTY Gunk engine cleaner, let it soak for a few days to soften up all the 'goo', then pressure wash. Then soak kit down with Simple Green CRYSTAL (clear color,more concentrated than traditional , no smell,). Of course, it is even better to accomplish this with a steam jenny... that will just about even remove the rust off steel, but exposes the raw steel that has been previously 'protected' by all the oily goo.
Oven cleaner is pretty good at removing grease and crud. Spray it on and let it soak a while and hose it off. I followed that with regular degreaser and another hose off. Of course as with any cleaner, scraping the heavy stuff off with a putty knife first helps a lot. Word of caution, don't breath in the fumes! And keep it off of aluminum parts like fuel pumps, it will discolor the aluminum. Definitely use this method only when planning on painting. Worked great for me when I rebuilt the front suspension as I was repainting everything anyway. A lot faster than Gunk or the Purple stuff.
I've had good luck with oven cleaner and Simple Green. Spray it on and let soak. I try to keep it wet for a couple hours before spraying it off. I have used mineral spirits and scrapers/wire brush on really caked on areas before using oven cleaner or Simple Green. Make sure to rinse well and wear eye protection.
For God's and our children and grand children's sake, please consider the environment where ever you end up degreasing it. Is the body off the frame I hope? All That stuff ends up somewhere when off the frame, also keep in mind that greasy gunk chunks dont disappear once blasted off the frame and will track around on anything that happens back on it and all over you when blasting it with any hydro spray. That said, tarp ,cardboard, plastic whatever under it and just scrape off as much as you can and dispose of that gunk safely. In a safe place considering the run off, use a microbic biodegradable topical solution and apply liberally and allow to soak. Be patient , look again and scrape and contain mess, and apply solution to spots that need it. High pressure washer / steam blast does the job, again, it can be messy and wet first time. I also suggest getting phosphoric acid and apply to bare , dry metal when done....of coarse neatly and keeping your environment in mind throughout the entires process....
i used purple power. they sell it at walmart or any auto parts store. it works good. spray it on let it soak for an hour then high pressure spray it. some spots took a second application but most came off first one.
