My 95 civic coupe DX MT seems to be burning oil, because in a week the oil level dropped about a quart, and there do not seem to be any oil spots under the car...

What would cause this... I'm only a beginner tinkerer when it comes to mechanics, so my mechanic friend helps with work on it. I'm being told this would be caused by the piston rings.

If so, how long on average would it take to replace them?

 

Check compression. Rings might be worn but fine. Could also be burning through the valve seals.