Guys,

I have been "chasing" a similar coolant system (possible head gasket
leak) issue for a few weeks now on a 2.1 with lots of miles on it. In
some cases I have just needed to do the obvious, such as replace worn
(and leaky) coolant system plumbing such as  a few hoses, pressurized
tank and thermostat. I still have a intermittent drip at the thermostat
housing but have a new one to replace this with.

I suppose that with an old worn engine a variety of things can happen
together that can make pinpointing problems harder and with this said I
have a suspicion that I might also have a head gasket problem that is
maybe contributing to a higher than normal cooling system pressure?  I
am not seeing any bubbles in the coolant tank though I have occasionally
( once every other week at startup) had a cloud of white smoke emitted
from the tailpipe. Perhaps this is not related though. Other than this
the engine is running fine and has plenty of power and is not
overheating nor (other than the few leaks) consuming a lot of coolant.

The notes on pressure testing the cooling system found at :
http://www.vanagon.com/info/articles/head-replacement.html   are helpful
in attempting to pinpoint a leaky gasket as well, though they do not say
anything about cylinder compression test results.

My main question at this point is,  do the following cylinder
compression tests ( and plug inspections) definitively point to a leaky
head gasket or do i need to dig a little deeper and  do a cooling system
pressure test?  If this is a head gasket beginning to leak should I
expect it to get worse quickly ? Or do I have some time to plan for
engine work. Put another way, would I be unwise to take the car on a 600
mile trip next week?

#1   110   plug noticeably cleaner and lacking soot and shinier than one
would expect.
#2   120   plug tannish
#3   120   plug blacker but ok
#4   140   plug blacker but ok

Thanks for any input from those who have been down this path before !

-john