I have a 2005 with a little over 220,000 miles. Haven't had the truck long, maybe two months but I have noticed what I believe sounds like valve train ticking. Not really noticeable at idle but going down the road I can really hear it in the cab of the truck. Sounds just like valve train ticking due to a loose rocker. Been watching some YouTube videos today and it actually has me worried that my truck is going to need a set of injectors. First thing I want to do though is go buy a feeler gauge and go through and check the valve lash on all the rocker arms. From what I've seen on YouTube seems to be really difficult to tell the difference buy sound weathere it be rocker arm tap or injector. I do not have any of the tools that some people have mentioned in the videos to isolate injectors. Do you guys have any tips or suggestions on how to check them? 

If those are original injectors time to change them. Injectors in common rail trucks should be changed every 100k miles for safety reasons. If you overextend the use of the injectors you take a risk of melting down the engine. I highly suggest you look towards new injectors like BBi. Yes, the price is steep but at least they are truly new injectors. 

 

Valve lash is a maintenance item. Most people don't keep up with very well. I would run through the valve lash when you take the valve cover off for the injectors.