Q&A

I recently found my engine coolant tank empty. I filled the tank with Prestone antifreeze (and didn't dilute with water).
Later, I checked the tank, intending to add water, but found about 3 tablespoons of brown gunk at the top of the tank. I spooned this out, and added water, but realize I have a problem.

Apparently I have loosened up some rust in the engine? How can I best recover? Is it possble to flush the system, or must I also replace the radiator. Or is the problem hopeless, and maybe I should simply junk the car.

The car has 90K miles on it, and also has an oil leak, A/C problems, needs brake work, and soon will probably need a timing belt.