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.

 

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.

 

chuck <chuck@localhost.localdomain> wrote in
news:slrndlcato.6ma.chuck@localhost.localdomain:

>
> 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.



Something is seriously wrong here. Are you saying the expansion tank has a
pressure cap on it?

On your car there should be an 0.9-bar cap (13lb) on the radiator. This cap
should allow pressure to bleed off into a tube in the rad filler nack that
goes to a non-pressurized expansion tank.

Is the rad cap aftermarket or OEM?

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TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/