Are you getting any error codes, or just a noise? Changing the adjusters is a major job on that engine. I doubt it's the chain adjuster (i.e. tensioner) as it is fixed, and if it broke, it would rattle continuously. The magnets (i.e. solenoids) won't cause any noise - they are just stationary magnets. It's the adjusters that actually move and do the work. If you have no errors, I would suspect something else - adjuster problems should throw errors.