I've read here and on other forums about the 6.4 engine "tick" at idle and lower rpms. My truck seems to have it and it seemed to be getting more pronounced. Took it in and my dealer's service manager listened and said it was normal but after listening a few minutes - said he wanted one of his guys to check it out. They went through diagnostics along with compression tests and said that all was good and it was "injector rattle". He said a couple of them were louder than the rest - but working fine. My question is this - Is there such a thing as injector rattle and if so - will this jeapordize my engine? Truck runs fine - just want it to stay that way. btw- dont know if mileage is a factor w this- but it has 78k on it. Thanks for any feedback!

 

Just a thought, but my truck was having a knocking lifter sound recently and it would come and go. I thought the worse, but it turned out to be an idler pulley. The dumb thing even seemed to come and go with rpm and temperatures. Like you said, my truck was running great, but with an annoying knock.

Good luck!