On 10/19/05 6:24 AM, in article slrndlcato.6ma.chuck@localhost.localdomain,
"chuck" <chuck@localhost.localdomain> wrote:

>
> My 91 Civic presurrizes the cooling system upon startup. The overflow
> tank is also under pressure and there is a slight leak under the cap.
> There was also a spare cap under the hood when I bought the thing not
> long ago. Is this pressure normal or is the head gasket going? There is
> no oil in coolant, no coolant in the oil, and it doesn't smoke. It runs
> good and doesn't overheat. But if you start it with the cap off it
> sprays coolant. Should the overflow tank be vented? I only see one hose.
> THanks in advance.

Look carefully at the tank itself, there should be some sort of overflow
tube built into it. I've never encountered a Honda with a pressurized
overflow tank. My guess is that your radiator cap is bad and the overflow
hole on the overflow bottle is plugged.