I got angry with my Escort this morning and decided once and for all to track down the horrible rattle at idle. I discovered that the rattle stops if I apply about 5lb of lifting force to the front bumper. The noise occurs because the two outer mounting tabs on the header panel are broken and the entire assembly, including the front bumper, resonates loudly when the engine is idle, warm and under extra load (e.g. AC).
An aftermarket header panel is less than $20 on ebay, and I'll replace it. But I wonder if I'm fixing a cause or an effect here. Is there supposed to be a support at the bottom of the bumper (some kind of strut or bar that holds the bottom of the bumper to the front of the radiator), to prevent it from rattling this way?