timing chain has been making noises for about 5 years

This damn timing chain has been making me crazy for over 5 years. There's always a noise when I start the car. The rattle has started & stopped making noise, too many times to mention over the years. Then a few months ago, the noise became constant, and my mechanic said it has to be replaced. Problem is the car isn't worth what it cost to replace the chain. The mechanic also said, they have had many problems after they replaced timing chains on Altimas before. The have had many occasions where the new timing chain, would also make noise.