Dan I've been researching this past week different types of hydraulic lifter ticks trying to chase down my problem. I just read the following yesterday for what it's worth...Intermittent hydraulic lifter ticking: There will be a few clicks and then it will be quiet only to have the noise reappear again. Intermittent clicking is usually a very minute piece of dirt that holds the ball check off the seat for a few seconds and then passes through. I read this off of Hemmings.com....The lost art of valve adjustments. Hope this helps you out some...good luck!