On Sun, 18 Aug 2002, Dennis Haynes wrote:

> Sounds kike a bad head gasket or cracked head. While the engine is
> revving, the combustion gasses are getting into the cooling system. You
> do not see the "bubbles" while the engine in being revved due to water
> pump pulling through the coolant tank. When the engine returns to idle,
> the pump pulls less allowing the air the enter the tank quickly,
> releasing the bubbles. This is why both the cooling systems on both the
> diesels and water boxers have problems after extended highway runs. The
> gasses keep building up until there is no place to go and they either
> vapor lock the pump or blow everything out the relief valve.

That's *exactly* the symptoms I had with a cracked head on my diesel
Westy.  While driving the combustion gases seemed to accumulate in the
radiator, in fact the entire top half of the radiator would end up *cold*.
(Bad, since that's where they put the fan switches.)

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
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