i have a 04.5 crew cab that seems to have an intermitant knock at around 1200 to 1800 rpms. i noticed after 20 min of driving my temp was only reading about 140 and the truck was making the knock yesterday the temp got up to around 195 and there was no knock would the truck not heating cause a knock at low rpm????:confused: the truck is bone stock i have a programmer but it just used for speedo calibration