[Vwdiesel] normal running temp

[LBaird119 at aol.com]

  VERY typical blown head gasket behavior.  (Until it's blown enough that 
a diesel won't start.)  Generally as the temp climbs on the gauge, the 
heater output will drop, maybe even to no heat at all.  Then when the 
gauge drops the heater will come back in.
  Yes, the small, coolant return line to the reservoir is a good indicator 
for a blown head gasket.  If it keeps spitting air or no water at all at 
a high idle then it's usually a blown gasket.
     Loren

In a message dated 7/7/2005 3:50:49 PM Pacific Standard Time, 
vwdieselbunny at yahoo.com writes:

> Mine was the same way, needle all over the place and
> coolant being pushed out after more than about 10
> minutes or so of driving.
> 
> I hypothesized that what was happeneing was that a
> tiny amount of exhaust was getting in the coolant,
> causing a bubble, which would block the thermostat,
> causing the temp to rise.
> 
> Eventually, the bubble would force itself past the
> thermostat, allowing it to open, and the engine could
> cool.
> 
> Then it would start over.
>