Have a knocking noise on hard acceleration. Took truck to Chevy garage and here is what they said. Technician took truck for ride. Everything sounds normal. Checked pressure on all injectors and said was fine. Nothing wrong with fuel system or anything else. Guess I will just drive it and see what happens.

 

any programs or tunes?

normally this kind of knocking is ether pilot injection turning off at higher RPM or if one or more injectors are dumping more fuel then it should.

when you say the pressures on all injectors where good are you referring to the balance rates?

 

Not sure exactly if it was the balance rates. The diesel tech said he checked all the injectors and they were good. First diesel pick up I have owned.

 

Does the knocking sound happen at around 2000 rpm or throughout the rpm band?

 

No tuner. Bone stock. Right around 2000. A lot more noticeable when cold.

 

well in some of the older model duramaxs the pilot injection would shut off at around 2000 rpm and the knocking sound of the diesel would become more pronounced but i dont think the LMM engine does this so it may be an injector but if all of the balance rates are good then ???

if the vehicle still under warranty? maybe take it back to the dealer shortly before it runs out to have them look it over and check the injectors health.