2004 oilpan
first KILL the rust with some thing like the
converter type stuff.
Here is some info on converters
Rust Converter Frequently Asked Questions | GEMPLER'S
http://en.wikipedia.org/wiki/Rust_converter
Most of the converters will leave a protective layer
that can prevent more rust from forming.
But you best bet is to put a good protective paint
on top.
Also if you do replace the pan when it off is a good time
to paint it. Strip it down to clean metal and use a metal
prep chemical. The next step will be to use a compatible primer
followed by a good paint. Epoxy paints come to mind. Not cheap
but will give you a good life span.
Sean







