My arm crackle and pop almost every time when i open it but without pain.it's maybe something on the joint of my elbow (upside front). what is that ?

Crackle and pop: You may have an exostosis or a bone spur on your elbow causing your crackling and popping.

Fluid dynamics: There are two main schools of thought as to cause of "joint noises." first being rapid displacement of fluid in the joint, which if noise is ongoing, may be an indicator of prior injury and self-protection, which should go away in time. Second being tendon / ligament laxity causing noises (possibly so far as subluxing joint, if follow chiropractic model)--that tends to worsen over time.