Question: What is the purpose of the PCV valve and what are the symptoms when it goes bad?

Answer: PCV means positive crankcase ventilation. This valve uses vacuum from the intake manifold to draw the fumes from the crankcase. Symptoms of a faulty PCV valve are poor idle and excessive pressure in the crankcase.

Source: http://www.2carpros.com/topics/pcvvalve.htm

Now Im not very familiar with PCV's as my civic doesn't have one. However, your symptoms are those of shot rings. Take it to a shop that can perform BOTH a Compression, AND a leak-down test. A leak-down uses compressed air, so be sure they know what they're doing. Some shops confuse the two.. don't ask me how.

Do this to get definate results man.