I have a '93 coupe with about 150,000 miles. All stock.
When going over railroad tracks or dips in the road I hear a scraping sound (similar to a plastic lip spoiler scraping the road). I hear the sound from both front and rear, and each one in succession as that axle compresses over the bump/dip. This started last winter, but seems to be getting worse (does it on smaller bumps). The struts are original, I don't notice any obvious signs that they are shot (unless this is an obvious sign).
Any ideas?
How many miles are the original struts typically good for?

 

since its the original struts, and you have that many miles on your ride chances are it would be a good idea to replace them, you can do it yourself. Its not that expensive