"TE Cheah" <no@spam.biz> wrote in message news:43f8b575_2@news.tm.net.my...
> | dissolved gasses are driven off
> To where ? They cannot escape when radiator cap is closed, & will re
> -dissolve into coolant ( when cool ), esp CO² ( quite soluble in cool
> water ).
>
>
Under normal conditions the coolant cycles to/from the reservoir when the
engine is run. Whatever bubbles collect in the radiator should get cycled
out to the reservoir each time the engine warms up. I am more than a little
concerned if bubbles appear on a continuing basis more than a few days after
the system is filled. OTOH, if it is the head gasket dying the symptoms will
soon come on strong, as you say. Within a month or so you should know one
way or the other.

A common shadetree check for head gasket failure into the coolant passages
is to remove the radiator cap (with the engine cold), start the engine,
pinch off the hose to the reservoir and place the palm of your hand over the
radiator opening. If combustion gases are leaking into the coolant you will
feel the steady rise of pressure against your palm within a couple seconds
and there will be no mistaking the pressure within less than 10 seconds. By
the time you can feel fluctuating pressure the gasket is very far gone - I
don't recall feeling that on a car that still ran.

Mike