hissing noise

So last night i hit a deer

i get home and notice the damage is actually minimal, bodywork-wise. however, the grille was toast, front of the hood looks like tinfoil, and when i shut the car off a high-pressure gas hissing noise was heard from the radiator area. however, no steam was observed, and i couldn't pin down the source.

i assumed it was my radiator, and the coolant system. i went in disgusted and figured i'd come out to a puddle of coolant in the morning.

this morning, no coolant loss, car starts ok, so i let it heat up to try and reproduce the hissing noise. i got it into normal operating temp and left it for a while, shut it off, figuring that if it was steam in the coolant system or radiator i would be able to reproduce the sound.

no sound.

question: is there some other gas besides steam from the coolant system that would've made the noise? is the radiator filled with something that could've leaked once and now is depleted?

i'd appreciate hearing from anyone with any insight on this.

thanks ahead of time.

edit: the car is a 2005 Legacy GT base model

Is your AC working??
The noise could have been leaking refrigerant.

Dang this is an old thread, but oh well.

The other night I noticed my hood wasn’t latched down all the way. I pushed it down; it latched and produced ‘the hiss’. I tried to reproduce mine as well and couldn’t. No fluid, no steam, just this hissing. I am pretty sure it was coming from the radiator. I turned my car off and it was still hissing, touched the back of the radiator and the pitch of the hiss changed.

Anyways, plan on looking at it a little more when I get some time. I think my first start will be to pressurize my system. I will update if I find anything. (mine is a 96 legacy, 2.2)

Found it. . mine was my AC condenser.

bump.. so i scratched the front of my radiator tonight installing some aux lights. there is now a "hissing" sound coming from where i hit the front of the radiator, where there's a stream of air blowing out. im not losing any fluid, yet anyway. im seeing A/C condenser above me ^^ any other knowledge on the OEM radiator ('06 2.5i) and what I would have hit/should i drive on it if im not losing fluids/etc?

Thanks

the a/c condenser is the front-most heat exchanger on the car. engine cooling radiator does not have pressurized air in it ( ) and is behind the condenser. unless you need your a/c to work right now, there's no harm in driving it with a punctured a/c condenser.

no need for a/c in WA right now. feeling like a dumbass that a) my drill bit slipped and b) i didnt know what it slipped into. thanks for the response, i had come to the same conclusion.

cheers