hi. i have a problem with the knocking i checked injectors and every thing is ok

my mechanic said that is a piston slap, but i doubt because car run ok,no oil
consumption , temperature is ok, is just the knocking noise on low rpm

any advice pls !!!

 

You need to establish whether it is abnormal diesel knock due to fueling issues or whether it is mechanical knock which can eminate at different frequency from many components. e.g piston slap, bearing knock or the valve train.