Answered your question on another forum, but for info purposes here:
Me: I'd be willing to bet money he put a 2006 1500 hemi in it...problem is he (or whomever supplied the engine) did not realize a "1500 megacab in 2006" is basically a 2500. Who installed it? Default position for MDS is deactivated. Requires a PCM signal to activate it. As long as the solenoids are in the block but unhooked, it will function normally unless something has been screwed with.
Cnice22: Its a 06 engine but they probably did get it out of a 1500 imstead of a 2500 which your right about the megacab basically being a 2500 but i could put the solenoids back in an it will work fine? An i imstalled it my self my truck was not wire for mds so i took them out not knowing it would do this.
Me: I knew it LMAO!! Put the solenoids back in and leave them. There's oil pressure lost through a port if the solenoids aren't there and you use MDS lifters; they collapse. Other option is to yank the heads and put all non-MDS lifters. Either way...a little research up front goes a LONG way vice charging in head first.
