"bob haller" wrote in message ...
On Saturday, April 18, 2015 at 1:45:46 AM UTC-4, Snuffy Hub Cap McKinney wrote:
This is more of a Sherlock Holmes type mystery than a practical matter.

Neighbor has a leaking head gasket in his Buick bad enough so that the engine runs rough all the time. Watch does with it is not my concern.

When driving it runs cool. When sitting idling the temp increases rapidly. If he puts in neutral and revs the engine, he says it drops to normal quickly. Radiator, fan clutch, thermostat, water pump all checked out and working normally.

I'm wondering .... when the engine is turning slowly, if the the coolant pressure drops, which could be letting more exhaust leak into the coolant and raise the temp? Says when the temp goes high, he can smell antifreeze, probably blowing out the overflow.

- most head gasket leaks crate white exhaust.
-
- if coolant leaks into oil engine will soon be siezed

Milky coolant from engine, but no water in oil.