Hi i am Dr Ahmed Aly  
  thanks for using HealthcareMagic site ,
I had gone through your question and understand your concerns ..
    In my opinion you may have a kind of 
tendinitis or your 
cartilage surfaces become more rougher or ligaments tightening .
   I do not want you to be worried unless these sounds are painful , you may try to decrease your weight , avoid heavy lifting , vigorous movements , bending your knees for a long time and bad sleeping and sitting postures .
   Using hot massages with topical gels of anti-inflammatory and some physical activities like morning jogging will be helpful.
  If these sounds became more painful i recommend you visit your physician for proper evaluation and management and prevent further complications . 
Please click and consider a 5 star rating with some positive feedback if the information was helpful. Wish you good health,
Any further clarifications feel free to ask.