Rocker Arm Problem

I had a small tapping noise coming from the passenger side valve cover. You couldn't hear the tapping at idle, but while driving around 1200-1300rpm, you could hear the tapping and also the car had a hard time idling. I just installed LS7 lifters back in June '08. So I proceed to pull the valve covers and afterwards, I grab a flathead screwdriver and began to tap the rocker arms from the side. All were tight except one. It moved side to side and up and down freely. I even grabbed it with my hand and raised the rocker up and down. (it was just flapping). So then I grabbed an 8mm socket and tried to tighten it, but it was already tight. So I took the rocker arm off. I turned the motor over about an 1/8 way and put the rocker on the pedestal and bolted it down and the rocker didn't move freely anymore, it was tight. I left it like that then went inside to finish watching the Giants runs over the Browns, but fell asleep afterwards. I drove my alt. vehicle to work this morning and I was just thinking while here at work. My question is once the motor makes another 1/8th turn or a full turn, will that rocker arm have the same play in it as it did before at the same position it was loose? Or should I tighten it, then rotate then motor and see if it tightens some more?

CAR: 2002 Corvette C5 MN6

[c4c5specialist]

HI there,
Remove the pushrod, it may be bent.
Allthebest, c4c5

Originally Posted by c4c5specialist

HI there,
Remove the pushrod, it may be bent.
Allthebest, c4c5

Push rod is not bent.

[c4c5specialist]

Somthing is bent or damaged if you have no preload on the rocker arm.
LIfter could be collapsed, valve stem could be bent, but SOMETHING is wrong.
When you rotate the engine, you could be on the ramp of the cam lobe so all the lash is taken out.
Allthebest, c4c5