The manual CCT doesn't need to be adjusted that frequently, I've had mine in the same position (granted your timing chain isn't ****ed and stretching) for about 8,000 KM before I went to adjust it, and it still didn't need it.

I'd rather spend 2 minutes tightening a bolt than replacing the whole thing not knowing when it's gonna seize up again.

 

perhaps since it is only at idle perhaps it is an oil issue. when was the last time it was changed and what weight are you using. things along those lines, if everything else is checking out. just thinking outside the box

 

I changed the oil about 500 miles ago, and I am using gtx 10W-30.