i have a 97 silverado z71 and at regular idle the engine sounds fine giving it a little gas makes a ticking/knocking noise it is more noticible in reverse than in driveive had where the torque converter bolt had came loose and was rubbing on the dust cover and i checked that again and all of the bolts were tight i had to replace the crank and one rod bearing and connecting rodat the start of the year and it has ran great no noises and now i am having this problem and i am hoping its not a rod bearing again