My 2005 Kia Rio is leaking antifreeze in a slow drip. Dealership says they can't

[sarah a]

find a leak!? I only notice this leak when it gets around 20 degrees (F) or less. The day I took my car to the dealership for the 60k mile checkup, it was much warmer and they said they could not find any leaks, nor could they force it to leak with pressure. My car is not overheating and seems to be running fine (despite the fact that it's 10 degrees outside) but drips pretty steadily in the really low temps. I'm wondering if it's possible that some components are shrinking/expanding at different rates than others within the cooling system. If so, does it require immediate attention? This car was purchased brand new in California, and this is its first winter in sub-zero temps. Do they make an antifreeze of a different viscosity/composition for cold weather?

 

[Will S]

Obviously the tech that looked at the vehicle doesn't know what he's doing. I would go to another shop and have it pressure tested (drop the car off for a couple hours and let them keep the pressure tester on it) and this will find the source of the leak, even if it is slow.