Hey I own a 2014 A4 S-Line auto with 93k miles it started making the same noise you’re describing, 2 months ago i replaced the timing chain cover gasket because it was leaking and checked the chain, it felt normal tight as it should this noise is becoming more regular. 2 questions how much would a rough estimate be of the job and how do you find a trusted European mechanic or going to the Audi dealer is a better option