I have a 2015 Infiniti QX 80 with 135k miles that began running bad so I brought it to a mechanic shop and they replaced the VVT’s. When I picked up the car from them, it was still making a clicking noise, but they told me that that noise was likely coming from the fuel pump. Less than two months later, the timing chain broke and caused catastrophic damage in the engine. Should they have a checked the timing chain at the time of replacing the VVT’s? Also, should they have checked the oil and oil pan for metal debris? From what I understand the timing chain should be replaced between 80,000 and 120,000 miles so I’m not sure why they didn’t catch this problem before it became catastrophic.