May I call you Vincent?

This is a much discussed issue, under my name in the archives you see
one theory dealing why heads leads and what can be done. Here's the
abbreviated version.

Thick cooling jacket gaskets are needed, and must stay pliable, to
compensate for a reduction in clamping force as a result of dissimilar
contractions of long steel studs and aluminum water jackets in cold
weather, not an issue when the engine is at operating temperature.

The need for an aggressive water pump to move the coolant through the
length of the van and back. If you have an overnight cold soaked engine
and the temperature is cold or below freezing  and you then  start the
motor and then drive the engine at 3000 + RPMs before the thermostat
opens, the pressure in the cooling jackets would be at a maximum when
the clamping force  of the system is at its minimum. Result, coolant
gets forced beneath the seal.  This coolant become corrosive and over
time the heads pit.

  I also have the notion that the VW coolant contains an additive to
keep the seals pliable or swollen or something that aids them is
performing well.

I believe if you warm up commensurate with outside temps and keep the
engine below 2000 Rpm, until the aluminum expands , you can alleviate
this issue, I wait until I see the temperature needle reach the bottom
of the first white hash mark.

Sincerely,

Mark Keller
91 Carat
Cowichan Bay, BC.