clicking valves?

I just bought a 1993 xj 4.0 auto with 122,000 on the clock. I changed the oil a couple of days ago and I put in Valvoine 's "Max Life" The stuff for motors over 75,000 miles. I now get this clicking noise near the top of the motor. It sounds to me like one of the valves. But it comes and goes. It starts out quite and gets progressivly louder, and then it will just quit and sound normal for a few minutes. Then it comes back. Any Ideas? Also, when I changed the oil, the dipstick showed that I was half way into the hash marks. Now I am almost to the add line and I have only driven 100 miles. Before I changed the oil, it was pretty low. But I don't burn any oil. No blue smoke. But aside from all of this, the motor runs great and strong. If anybody has any ideas, I would appreciate it.

Thanks

You might have a lifter that is acting up causing your "clicking" sound. At 122K the engine is just broke in, seen on this forum 4.0's at 300K+.
Do you have any noticable oil leaks, is there any oil in the air box? The rear mains have been known to go out at 100K.
What grade of oil did you put in the engine. With that kind of milage, I would suggest running at least 10w30. Also try Lucas Oil Stabilizer, just like SLICK 50 basically, on your next oil change.

I used 10w30 when I changed the oil. And I also just changed the air filter. I didn't notice a bunch of oil in there. I have noticed that there are some wet spots on the motor near the back of it. But I haven't noticed a bunch of oil puddled up on the ground. I would think that if it were leaking pretty badly, I would have a little bit of an oil spot forming on the ground.

I also own a '93 4.0L with 221000Km. I occasionally get the sticking valve as well. I try to keep my oil level right to the top of the full indicator on the dipstick. You can try adding half a litre of ATF into your oil. As far as leaking goes, I recently replaced the valve cover gasket as mine was leaking. It stopped all of the leaking I had around my engine and it is an easy job to do. My enigine doesn't leak but it does burn a little bit of oil.