2012 Sportwagen - Loud hissing sound when car is turned off

Last night, I parked my car in my garage and I could hear a loud hissing sound coming from the center of the car near the radiator. It was leaving a wet spot on the front grill. I'm unable to get a good look at the source though as the front grill is in the way.
I am not getting any dash errors, the car appears to idle fine and the engine was not overheating. The city spreads rocks around in the winter for grip. Could a small stone flying into the front grill have pierced something? Is this something I need to be worried about? I can't get to a mechanic before Tuesday. Thanks!

coolant leaves a pink chalky trail once it dries. dip a piece of paper town in the wet spot to check color and smell it. the coolant rad is sandwiched between. The front one is your a/c condenser. If that got punctured your a/c wont work and the spot you see is oil.

Thanks for the reply! I took a look at the residue from the leak. It's pretty much evaporated now but I couldn't see any pink residue. I went for a drive today and although it was hard to tell if the A/C was working or not (currently -11c/12f) the car didn't overheat and appeared to be operating normally.

I think the button wont light up if its not working. Also would throw a code that you could read with vcds. and if your coolant gets low, it will throw a light and give a warning.

also sometimes it sounds like pressure escaping. but is actually just the high and low side in the a/c system equalizing.

a rock could have come up and hit the condenser or radiator OR the intercooler. if its the AC it wont happen again as you will have lost the charge. if its coolant you will have a puddle under the car. if its intercooler, it will hiss every time you make boost and if its big enough it will throw a CEL.

my hunch is that its coolant. find the leak and report back. you can put UV dye into the coolant system to help track down EXACTLY where on the radiator it is if you cant find it. it could also just be a hose going bad. either way i would not drive it if you find coolant on the ground until you fix it, easy way to total an engine by warping the head. and for what? a few bucks in repairs? if it is the radiator with a pin hole, it can be fixed for cheep with some epoxy but it needs to be done correctly. there are other products too. let's just start with where its coming from and what it is. If the AC won't blow cold anymore then that's the issue. i would still fix the leak and vacuum down the system and purge with nitrogen even if you let it wait till summer to fix. DO NOT let a AC system open to the air.

I took a good look in and around the engine for any kind of pooling and came up negative. I was concerned as I had to pick a family member at the airport. 1 hr drive later and no CEL, Temperature reading normal and everything sounds fine. Coolant levels are good too! I really hope/think it's a perforated A/C. I also noticed that a thin wire mesh was pushed way up towards the hood. Had it been pulled down to protect the condenser it would have prevented this i think. It's going into the shop tomorrow to be diagnosed. I'll update for posterity. Thanks again, you guys are great!

Just got back from the shop. Diagnosis: punctured A/C condenser.

yirra said:

Just got back from the shop. Diagnosis: punctured A/C condenser.

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if you dont want to fix it now, but keep the system in healthy status but are going to replace the condenser. find the leak, cover it up with epoxy (have the system vacuumed down till it rests at 250 microns then have it charged with nitrogen. this will keep things nice and healthy but your system is going to need to be flushed and repaired PROPERLY. you can DIY this, dont rely on 99.9999% of guides out there because they are all wrong. but if you do DIY this, plan on about $300 to $400 in parts and tools to do the job. you need nitrogen if you DIY, and no one talks about it.
food for thought.
IMO its worth it to have a REPUTABLE shop fix and service it because if it stops working for any reason then they will fix it as per the warranty they cover on the work done. doing this yourself can easily junk a few bottles of 134a and nitrogen cost and a new dryer filter and a lot of time.