I had other threads about tracking down what seemed to be a new mechanical sound coming from my engine. It seemed worse when the temps were cold (in the teens at night), but it would get better as the engine warmed up. In cold weather (below 40) it would seem to be there at some level. It sounded like a mechanical knock that was coming from the engine, and possibly even a single cylinder. After reading the posts here, some said it was injector hammer, but one hinted at piston slap. It sounded so mechanical, I thought for sure it was piston slap.
Today, the outside temp was in the 60's. The knock was non-existant, even when the truck was started cold this morning. The engine ran smooth, and it sounded like my old engine (I bought the truck used this past summer).
Ok, so what are the cures?
Also, what's the diagnostic box some of the guys here are building to cut out injectors? Do they simple ground the signal going to the injector? Maybe I can track it down to a single cylinder.