My 1998 Honda Civic began making a clicking/putting noise which increases in frequency as I accelerate and decreases and eventually extinguishes when I deccelerate. It is loudest with the windows closed so it doesn't sound like it's coming from the outside. I did recently hit a large, wide pothole at a decent speed. Any ideas about what this might be? I'm supposed to drive about 300 miles this weekend and don't want to drive if it will hurt something.