Strange crunching noise coming from my left elbow

Hi , I have started to hear a strange crunching sound in my left elbow when i do deep locks and when i do dumbbell shoulder press in the gym. I dont have any pain or any swelling but it concerns me because i dont want it to develop into anything more sinister. I am 50 years old now and i started climbing when i was 13 , i climbed solidly until i was 32 and then i stopped. I started climbing again in April 2011 after a break of 17 years or so . During that time i did mainly weights and two years and a half years ago i weighed in at 95kg but now i am 78kg and wondering if this noise could be age related arthritis or something to do with a reduction in muscle mass etc. I hope you can advise on what steps to take because other than a spell of tendonitis last year i have never had a climbing related injury. Regards Alan