Here's my 3 cents - drain coolant and replace with VW coolant (yeah, it's
almost $20/gallon but worth the extra insurance over stuff like sierra.
Strange that they don't have as many head gasket problems in Europe. Also,
tucked in the owners manual is a secret to the life of the VW head gaskets.
It says never stop the engine immediately after a highway drive. Worst you
can do is pull off highway in to rest area and turn off engine - let it run
for 2 min. The earliest car engines did not even have water pumps - cooled
by convection. The VW is a horrible cooling design as there is no natural
convection flow. What happens is that you have very hot engine and turn off
engine means there is NO coolant flow any more. Super hot heads have no
coolant flow over them, and coolant temperature can exceed the coolant
boiling temperature - pressure goes sky high locally and head gaskets go
"pop." This is called "heat soak." Don't belive me - just read your owner's
manual. Ok, to avoid questions from list members I went outside and got my
owner's manual(s). Here goes - PAGE 25 (1985 manual, PAGE 28 1986 owner's
manual) "DO NOT STOP ENGINE IMMEDIATELY AFTER HARD OR EXTENDED DRIVING.
KEEP ENGINE RUNNING AT INCREASED IDLE FOR ABOUT TWO MINUTES TO PREVENT
EXCESSIVE HEAT BUILD UP."

Interesting, huh?