It cud be chondromalacia patellae. Generally happens in ur age group. Hav u had any injury directly or indirectly involving knees? What positions gives dose sounds? Anyways u got to see an Orthopaedician. Later on things would depend on that. For Time being u can apply cold or do hot fomentation.

Hi, this is Dr Hitin Mathur from Fortis C Doc Hospital, New Delhi. Welcome to Practo. As far as the pain and the noise in the knee is concerned, it could be coming from the meniscus or a hypertrophied plica in your knee. A good clinical examination is a prerequisite to find the cause of the same. You may need to undergo some imaging and blood tests as well depending on the condition of the knee. I would suggest that you see an orthopaedic surgeon as soon as possible before any permanent damage to the knee occurs...