I have a water/coolant leak that is not coming from the radiator but a tiny hole under the car and behind the radiator that looks like it wold take a plug

look for a leak from the drain hole under the pump housing, if no leak not a water pump
take the car to a radiator specialist shop and have a coolant pressure test done to determine where the leak is
if it has plastic tanks for the radiator , they split with time and leak under pressure and a pressure test will reveal exactly where the leak is unlike a guess

Hose ? The drain valve on the lower radiator ? The water pump has what's called a weep hole built into it. When the water pump fails water weeps out of that little hole to let you know it's bad. I think the ion probably has the water pump onth the front of the engine under the plastic cover ? ( not sure on that ) if it is the water will leak from behind that plastic cover making it look like its coming from the area where the oil pan and that plastic meet. It could get blown around by the cooling fan making it look a lot worse that it is. Check the lower hose and all the other coolant hoses for cracks or leaks as well as the entire radiator area ( sides, top, bottom ) check your rad cap when its cool and be sure the rubber seal on the inside of the cap is good and not cracked or dry rotted. If it is then when the water gets hot and pressure builds in the rad it will leak. When its cold it may not.

steady coolant leak could be coming from radiator hose at thermostat or water pump.check water pump weep hole and gasket for leak.check heater core hose leaks or look for leak at the radiator side containers.

SMOKE UNDER HOOD COULD BE COOLANT LEAK FROM RADIATOR ITSELF OR CHECK FOR LEAKING TOP RADIATOR HOSE AND CHECK FOR LEAKING BOTTOM RADIATOR HOSE.LOOK UNDER THE HOOD IF COOLANT BOILING OUT COOLANT OVERFLOW JUG ENGINE OVERHEATING FROM BAD THERMOSTAT OR BAD WATER PUMP.CHECK FOR COOLANT LEAK AT WATER PUMP WEEP HOLE.IF SO WATER PUMP NEED REPLACING.ADD MORE COOLANT UNTIL LEVEL CORRECT.TRY LOCATE LEAK. IF CAR OVERHEATED AND BOILED IT OUT. SMOKE UNDER THE HOOD CAN ALSO BE CAUSED BY LEAKING VALVE COVERS WHICH CAN BE FIRE HAZARD IF OIL LEAKS ON HOT EXHAUST MANIFOLD.

Possible leak areas waterpump, heater core, intake manifold gasket, radiator or hoses. Waterpumps have what they call "weep holes" which is an early warning system to prevent major damage when pump fails. The weep hole needs to be inspected from below and is usual behind waterpump pulley. If it's your heater core, you should smell anti freeze inside truck and in most cases windshield will fog up. Radiator could be pin hole to front side of radiator (which is buried behind AC condenser & grill) and if it was head gasket, intake manifold symptoms would be coolant in oil OR lots of white smoke from exhaust. Try parking it on a clean dry surface and see if you can narrow down area where leak is coming from.

TO FIX COOLANT LEAK.YOU HAVE TO LOCATE IT.BEST TIME FIND COOLANT LEAK WAIT UNTIL MORNING.ADD COOLANT UNTIL COOLANT LEVEL IN RADIATOR CORRECT. START THE ENGINE LET IDLE UNTIL START GETTING HOT.THEN TURN OFF ENGINE.COOLANT PRESSURE WILL PUSH COOLANT OUT WHERE LEAKS ARE.CHECK TOP RADIATOR HOSE AND BOTTOM RADIATOR HOSE.CHECK AROUND RADIATOR LOOK DOWN BELOW COOLANT FAN AREA BEHIND RADIATOR.LOOK FOR LEAKS AT RADIATOR CORES AND SIDE CONTAINERS.CHECK FOR COOLANT LEAKS AROUND WATER PUMP GASKET OR WEEP HOLE.CHECK FOR COOLANT LEAKS AROUND HEATER HOSES AND HEATER CORE.CHECK ENGINE CRANKCASE FOR COOLANT LEAKS.

sounds like a water pump, look close behind were cooling fan aitches to the engine, that is were the pump mounts to the engine....GOOD LUCK

If you don't know where it is coming from, you have to find that out. Check the location of the spot on the floor, if you don't have a floor, put down a piece of cardboard, locate the drip, then look under the hood for what it is that is leaking. It could be the overflow on the expansion tank, could be your AC condensate line dripping, could be one of those tiny coolant lines that return to the back of the engine, could be the water pump, could be a hole in a hose. I don't know why the pressure check didn't show anything, might be something else. Check it out.

i cant tell you exactly what it is cause im not ther but you have to go under the car and detect where the leak is coming from....try radiator stop leak if it is a smaller leak it will stop it for a couple weeks. if it is a large leak as i think ur saying go under the car get a rag and clean off the fluid. keep on looking towards the top(on water pump, on engine block by intake manifold)and see where its coming from...i had the same problem it was my water pump...if its the manifold and its small get hight temp RTV sealer an try that....could be loose hoses or crack in radiator...you gotta look. good luck

The leak is probably coming from your radiator's drain hole. Try looking under neath your car at the bottom of the radiator and see if the plug is in (driver side).