Spray On / Rinse Off cleaner and degreaser.

[CalG]

I use GUNK concentrate. Cut 10:1 with kerosene. The stuff really works.
It makes soap out of grease and oil, then hoses off. DO NOT APPLY TO WET SURFACES. It doesn't work that way.

 

[1Mech]

If you are doing smaller areas, oven cleaner also works.

 

[RjCorazza]

My vote is for Gunk degreaser for heavily soiled grease, and Oil Eater for routine degreasing / cleaning.

 

[hayden]

My vote is for Gunk degreaser for heavily soiled grease, and Oil Eater for routine degreasing / cleaning.

Last time I used Gunk the instructions said it was important to warm up the engine first so it was working on a warm surface. That did seem to matter. Is that still the case? I haven't used it in a while.