I left my 03 Cummins at the dealership to replace the leaky axle seal, and since it has had a metallic knock for about 5000 miles (which I had thought was injector knock) asked them to listen to it. He insists that there is nothing strange about the noise, and stated that 'as these engines get older they make different noises'. I asked him if he had done an injector isolation test to see if there was a noisy injector, and he states ' as there are no driveability issues, there is no need to do that test.
Question:- is he being straight, as I thought the noise was due to carbon, which would eventually cuase the injector to leak, and do they begin to make 'new' noises as the mileage builds............it currently has 50000
Thanks in advance

 

mine has a little bit of a tick to it that goes away once off idle or under load. to me it sounds more like a lifter since it only does it when cold.

these engines dont need a valve adjustment untill 150K and if it was a leaky injector you would have decreased mileage and the engine would sound close to a 12 valve.

you could have some carbon buildup on the injector tip, the best way to remove it is to put the engine under as much load as you can and put the go pedal to the floor a few times to get the cylinder pressure up to burn it off.

now I'm no Cummins mechanic and this is only my personal opinion