On Wed, 04 Nov 2009 10:32:29 -0800, Gene Wagenbreth <genewxxx@isi-OS4>
wrote:

>I have a 1990 Honda Accord. It usually runs with the temperature
>guage in the middle range. Frequently the guage will quicky go up
>to close to, but not at the high end red mark. This happens even
>when its 50 degrees out and I am going 45 mph. If I turn on the
>heater the temperature usually goes back to middle. It goes down
>very quicky, within 10 seconds of turning on the heater. I dont
>believe the heater could cool things off that quickly.
>
>I have a new radiator and antifreeze. I am not loosing coolant.
>
>Could it be a hose or chamber that is blocked/pinched, and turning
>on the heater is allowing the coolant to byupass the blockage ?
>
>Any helpful comments appreciated.
>
>G

Head Gasket ?