I replied to this last night but it didn't post for some reason. But anyways...
"Smallengineguy - Get an engine stethoscope and see if you can pinpoint where it's coming from. It may indeed be a lifter. Once the oil thins out, the lifter collapses. Is it skipping?"
My mechanic had tried a stethoscope months ago and couldn't find the tick. Also, it isn't skipping but it does have an idling problem. It's supposed to idle at 700 RPM's but most of the time only idles at 400 sometimes even down to 200, so the gauge says. I have tried fixing that problem as well, by replacing the PCV valve, testing hoses for leaks by using carb cleaner spray on the hoses when the engines running to see if it stalls, and by replacing the ICU and none of that fixed that problem.
"RJ Gleason - Once the oil warms up and gets thinner, the lifter will not inflate as much and cause more valve backlash. (ie; the tick that you hear)
Often the fix for this is to take the valve rockers off and check for wear (replace if worn), examine the push rod to see if it is not wholey or partially clogged (if it is, clean it out or replace it.) Fill the rod with oil and use a air hose and blow the oil back into the lifter to inflate it. Reassemble and start it up, leaving the valve cover off. Watch to see that there is oil pumping through all the rods and then adjust rocker tension to spec."
The thing is, this ticking started a couple hours after I changed my water pump, the October before last. It is not the water pump or any pulley's since I had run my engine for 15 - 20 seconds w/out the serpentine belt on, and it still ticked. That same day I also replaced the distributor cap and rotor. Think I should replace the cap and rotor again to see if that itself is ticking, or is that very unlikely? I ask because I heard that, once the cap and rotor get heated up, if there's a crack or any problem with either, it can make a tick like that. I had gotten a quote for new rockers last year and to replace all of them on my engine, just for the cost of the rockers themselves, would be about $76. I just want to make sure it is not anything else before I go replacing them. If it is the rockers ticking, it would cost in engine performance too wouldn't it? I would guess that it wouldn't allow to let the valve or valves open and close correctly causing flow problems and hindering performance, correct? Thanks for all the help so far guys, have a good night.