jim beam wrote:
> Tegger wrote:
>> jim beam <me@privacy.net> wrote in
>> news:d-ednfLhtO5DtNHXnZ2dnUVZ_rKdnZ2d@speakeasy.net:
>>> BT wrote:
>>>> Car: 1999 Honda Civic CX (Hatchback)
>>>> Miles: 242,000
>>>> Location: Southern California
>>>>
>>>> Symptoms: Sweet smell when I started the car Monday morning. Thought
>>>> my daughter had dropped some candy or something and ignored it.
>>>> Tuesday afternoon, while driving up a hill at ~50mph, I noticed the
>>>> engine temp gauge needle rising pretty quickly. It got about 3/4 of
>>>> the way to the top while I was looking. I was in the process of
>>>> slowing down to make a left turn, so took my foot off the gas and the
>>>> needle went down as well. Made it back home driving very slowly, and
>>>> the needle never went above the halfway point (but it was still above
>>>> where it normally rests). When I got home, checked the oil level
>>>> (fine), coolant (near max) and if the rad fan was obstructed in some
>>>> way (it was fine). Drove normally to the dealership after about 2
>>>> hours, and the temp gauge needle was at it's usual spot just about
>>>> the 3/8 mark.
>>> gauge can't be trusted unless it's in the red - it's non-linear.
>>
>>
>>
>>
>> Maybe so, but my infrared thermometer tells me the gauge is awfully good
>> at informing you of overheating well BEFORE it gets into the red.
>> With a 78C thermostat, you're expecting about 205F at the upper rad
>> hose inlet at the head. As the gauge begins to climb above its
>> "normal" position, the temperature at the inlet will climb to well
>> above 205.
>>
>> Bottom line: Ignore the gauge at your peril! Once it lands in the red,
>> head and block wapage is a virtual certainty! Catch overheating early
>> and no harm is done.
>>
>>
>
> ok, i'm not saying "ignore the gauge", i'm saying that "usual spot"
> gives quite a wide range of temps.
>
> http://www.flickr.com/photos/38636024@N00/2445120839/
>

and that the gasket can be gone well before the gauge starts to show
problems.