2.4 liter valve noise?

Hi,

I've got a 2.4 four banger in my Carvan Minivan. Recently the clicking
valve noise doesn't go away entirely when warmed up.

I notice it driving around town below 40 mph. At higher speeds, I
can't hear it anymore.

Looking at a service manual, it seems like the hydraulic valve
adjusters are located in the rocker arms. Would it be possible these
could be worn out or malfunctioning? And if this is the source, I
think I can replace them however DO NOT know how to set up the
adjustment. I've worked on standard adjustable OHC engines of all sorts
but am NOT knowledgeable regarding adjusting the lash on hydraulic
systems.

The engine has 130,000 miles on it, the noise has been going on for
about 20,000 miles and engine runs fine with acceptable oil consumption
of about a quart every 1,500 miles. This van has been driven relatively
hard, at times at higher speeds on the interstates but cared for
according to maintenance scheduling.

Any advice would be appreciated.

Thanks, please reply to this list?

Harry