Preserving factory grease pencil markings

[Toro]

I would really like to clean up my firewall, but don't want to accidentally remove any of the factory grease pencil markings. Anyone have any tips or tricks that have successfully done this before? I'm guessing since it was written with a grease pencil, any cleaners for removing grease should be avoided. I'm hoping someone has found the right method. Thanks.

[Toro]

I think I'll start with just warm water first and try to get the top layer of dirt/etc off. Then probably go back with some of that car wash soap that isn't suppose to remove wax, go slow and see what happens.

[twoskies]

Hey , ive used gunk engine cleaner and not erased my marks, but ive used simple green also, i dont scrub on the firewall just spray on and wash off with my water on a sprinkle setting, Good Luck