Fishbone73

I recently bought a fresh long block and reman injectors as a combo deal . the injectors was installed by the shop I bought the long block from. Had engine installed and new sensors water pump oil pump. started it up and it runs and sounds good at ideal no leaks no blow bye .
As you place it in gear and start to accelerate it as a low rattle in top of engine till about 1600rpms had valves ck . its strong but . could that rattle be due to either wrong injectors or bad ones or injection pump issues . it just recently thru code p2146 for short in harness .So if any thoughts let me know ... thanxs