Folks, we had 1996 Tacoma with 2.7 that we had lower end rebuilt and a new head and an oil pump on. Customer brought it back with a load chirp after 1500 miles. We opened valve cover we see nothing wrong. Drained oil checked and for metal, nothing and even cut filter open and it’s clean. What do y’all think happened or is gone bad?

 

Can we get a little more info? Does the sound occur only at start up or all the time? Does it increase with rpm? Did you check oil pressure or compression? Could this be a failed bearing in the timing set? Who set-up the rotating assembly? Why was the bottom end rebuilt in the first place? Is it a knock from the bottom end, or a tap from the top end, or something different?