Coming home in 103 degree temp, I noticed that the coolant temp needle
was dead on middle.  The van normally runs a few mm to the right of
middle all through winter.  My previous 1.9L waterboxer engine ran at
dead middle.   I'm especially curious if the health of the van's engine
might be improving since the last set of repairs, which included
replacing 2 lifters.  Wishful thinking, or is there another reason that
the van would be running cooler going 65mph on the freeway for an hour
in hot weather?

The lifters did not resolve the obnoxious metal-on-metal ticking sound I
have from the center of the engine (used mechanic's stethoscope).  So, I
drive around in fear that a rod is knocking or a cam lobe is worn.  I'm
not prepared to crack the case open and find the source of the noise.
One of the cylinders is also firing off a little.  Oil pressure is okay,
for now.  Power is fine.  I can maintain freeway speeds with no probs.

Anyway, when I took out the two lifter, I could press the center plunger
on one of them in with hand-pressure.  On the other lifter, the lifter
piston  appeared solidly stuck in one place.  There was about 2
tablespoons of oil that drained from the pushrod top on the lifter that
I thought was bad.

I'm just collecting info to try and reduce my driving anxieties.  The
old van has stranded me on the side of the road enough times so that I'm
not too worried about having the engine die and having to call AAA
again.  Got Plus membership and it serves me well.  :-)  .  However, I
of course want to have more confidence and relaxation when I drive.  The
van's been running okay since I changed the starter several months again.

Any ideas why it would start to run cooler?