My car runs good and the only issue is a ticking that won't stop. on 2005 Mazda Mazda6

o you think it will be expensive to repair?
have tried STP and other lubes but issues continue.
Help !!!!! Want to sell car but can't with ticking noise.

1 answer
If it has adjustable valves then needs done. What does your owners manual say about the required maintenance? If it recommends adjusting the valves at 60-90k intervals or even as early as 30k, then start there and see if noise goes away.