I have a mystery leak I cannot locate. I noticed some coolant that had poured off the "ledge" that is the bottom of the front bumper cover when I had the car up on ramps when doing transmission fluid change. There wasn't a lot of coolant there but it is definitely coolant. It poured off that bumper shelf directly under the thermostat area where it has been collecting. FYI the previous owner had replaced the overflow reservoir decently and it still looks brand new. He had it filled with the green tinted fluid which I know is not correct but it's what's in there. I checked all the usual coolant leak areas mentioned in posts that I have researched here. I did it after the car had been driven then also cranked it and crawled under with a flashlight. There is no wetness at top of radiator pipe coming out of rad. There is no wetness around the water pump areas. There is no leakage from the tank nor signs of fluid on transmission top. The thermostat housing looks new and the coupling rubber connector to the metal pipe looks new as well - all those are dry as well. No wetness on driver's side at all. I don't see any wetness on passenger side of engine on top side where the piping connects to fittings. I've looked all over the engine and don't see any coolant leaks but there is the evidence of the small puddle that poured out when I raised the front end on ramps. I do however see some wetness on the bottom side of engine on passenger side on what looks to be the A/C component. There is fluid there collecting at the bottom of that part on two long bolt heads that secure that part to engine. It does have greenish tint but it's oily and not thin like coolant. I'm afraid that is AC lubricant oil. The AC system works great however and cools nicely. So any ideas where my coolant fluid could be from? It's a very slow leak as the tank level shows between Max and Min lines and I don't think we have put 1,000 miles on the car since we bought it. Only short trips and drives on less than 10 miles when we use it so far. Thanks

 

The coolant could have been from and old leak or a repair. The only correct way to search for a coolant leak is to conduct a pressure test of the system. If it holds pressure = no leaks. If it doesn't hold pressure you can keep it pumped up until coolant flows somewhere.
Go for the pressure test.

 

+1 on cooling system pressure test. Once the leak has been found, it is a good idea to change the coolant to the correct specification along with the cooling system hoses. Given the age of the vehicle, they are prone to failure and can cause overheating and catastrophic engine damage.