A finger follower is what rides the cam and hydraulic lash adjuster to make the valves move down.
The hydraulic lash adjuster is what pumps up to push the finger follower up against the cam to follow it's profile.
Either of these problems are easily fixed if the damage isn't to far gone. You'll need to pull the intakes and the valve covers to get at them. A mechanic's stethascope (SP?) can be helpful in finding which bank the sound is coming from. Be careful of moving parts using one though!!!
Changing the tensioner or timing chain is much more of a task for a beginner and probably better left to a professional. It involves removing the front timing cover, valve covers, intakes, etc just to get at them. Then there's the task of re-timing the cams again which is hard enough to explain to a seasoned car nut.
My bets??? Stuck lash adjuster. If the oil medic adative truely did anything, it was probably freeing up a stuck adjuster. I can't see where something like that would help the timing assembly since the chain would still have slop in it and the chain tensioner is mechanical, not hydraulic. Take it apart now and check it out if you want it done right and plan on keeping the car. The damage may already be done... You don't want to totally stick one of these parts or you'll end up with small parts bouncing around in the head destroying other parts.
As always, referr to CEG FAQ and your repair manuals to find out how to go about taking things apart and putting them back together. If you tackle a specific job, ask here or in the general forum for more tips and tricks.
