Tegger wrote:

> BT <bhthyagarajan@gmail.com> wrote in news:590dc13f-0fde-4e2d-851b-
> 52ba2b446f33@g7g2000prg.googlegroups.com:
>
>
>>On Jul 3, 6:14 am, jim beam <m...@privacy.net> wrote:
>>
>>>BT wrote:
>>>
>>>>Original radiator. And still in good condition according to the
>>>>dealer. All hoses are fine too. Their hypothesis is that the
>>>>thermostat went bad.
>>>
>>>if the thermostat goes bad, the gauge will show. if the coolant level
>>>drops, the gauge frequently won't. as grumpy says, with the engine
>>>cold, you need to regularly check coolant level in the radiator, /not/
>>>the expansion reservoir - any leaking means the bottle stays the same,
>>>but the coolant in the radiator disappears.
>>
>>Good call. The last time I checked the radiator itself was about 4
>>weeks ago when I did an oil change. It was fine at that time. And the
>>dealer said the coolant level was fine when they checked it. They also
>>couldn't find anything wrong with the thermostat, but suspect it was
>>stuck at some time, which may have caused the damage. This would be
>>the original thermostat. How long are they expected to last?
>>
>>I dunno. It seems like the head gasket just gave up the ghost because
>>of age or something. Do they have an expected life-span?
>>
>
>
>
>
> Sort of. At /minimum/ you're expecting over 200,000 miles from a head
> gasket.
>
> It's normally the "fire rings" that fail on an all-aluminum engine. Those
> are the parts of the head gasket which keeps combustion gases inside the
> cylinders. The fire rings can only take so much pounding over the years
> before they eventually develop weak spots that turn into gas-leakage
> points.
> Overheating (or near-overheating) accelerates failure of the fire rings
> through warpage of the head, as does corrosion due to neglected coolant
> changes.
>
> There are three things you can do to prolong the life of your head gasket:
> 1) NEVER allow the temperature gauge needle to rise much above "normal";
> 2) change your coolant every two years, even if it's the "long life" kind;
> 3) make sure your ignition timing is always kept spot-on (on cars with
> distributors).


And have the radiator serviced/cleaned (rodding) every ten years or 150K
miles. A partially plugged radiator will raise havoc with any cooling
system. As JB stated, thermostats should be replaced maybe every five
years and lastly, a faulty water pump should be considered. Sometimes
impellers can start to slip.

JT