I have a standard 1992 honda civic hatch with about 185,000mi and when I step on the gas there's a short duration scraping/grinding noise. It's especially noticeable in 1st or 2nd gear when accelerating from low rpm. When the clutch is out in neutral there's a similar sounding noise which disappears when the clutch is in. That, I think is caused by a bad throw out bearing. Are the two noises potentially caused by the same thing?

 

Couldn't say for sure if the two noises are caused by a bad throw out bearing. But it definitely sounds like you need to replace the bearing before the noise gets any worse. With a new bearing who knows maybe both noises will go away.