[Vwdiesel] Head gasket question

[Doyt W. Echelberger]

Last year My 85 Jetta TD got a new head gasket, because oil increasingly 
showed up in the plastic overflow reservoir, and a little coolant was 
disappearing every week in some mysterious way . I figured the oil was 
coming from a leaking head gasket, and the coolant was part of the same 
problem.

When we had the head off, we inspected the head, with special attention to 
the spaces between the valves. We saw little cracks in each of the 4 
spaces. List consensus was that the cracks were present on all the heads of 
the model, were superficial, and actually meant nothing in terms of leaking 
of fluids or gases between systems. Some owners peened them shut, some just 
ignored them.

My mechanic though differently, and held to the idea that I needed a 
replacement head.

I chose the path of least dollars and elected to put the head back on, with 
a new gasket.

The engine ran fine when reassembled, but over the next few months the rate 
of coolant disappearance gradually increased, and the engine operating 
temperature also gradually increased.

Last month the pressure in the coolant system went way up and blew a hole 
in the plastic coupler of the multi-branched coolant hose at the left of 
the injector pump (left, as you stand in front of the radiator and 
look  into the engine compartment.)

After the engine cooled off, I repaired the hole in the coupler (with 
epoxy),  put in new coolant, and started it up with the cap off the plastic 
overflow reservoir.  A thin stream of tiny bubbles showed up in the coolant 
coming into the reservoir.  I figured this is leakage between a cylinder 
and a coolant passage.

After we pull the head and look at everything, my mechanic is sure to say 
that I need a new head because the cracks between the valves are probably 
responsible  for the gases leaking into the coolant. He said that the last 
time. And new heads are very costly. Do you think he is right? Any way to 
test the cracks to see if they leak?

OK, so I'm back again, asking for input. All ideas are appreciated.

Doyt
Ohio, USA