Coolants gone but no visible leaks???? Just replaced therm and flushed radiator.

[Guest spiering.lucas]

So my car overheated this morning. And I popped the radiator and it was bone dry. I just did a thermostat on it last week and filled the coolant all the way up? Wtf? I have had the car for 6 months and previous to replacing the thermostat my old one was stuck open and the car never warmed up all the way but I NEVER had an issue with my radiator being bone dry. I'm pissed. I didn't replace the thermostat gaskets because the autoparts store gave me the wrong one but the old ones appeared to be fine and there is no visible coolant leak from around the thermostat housing. Could it be evaporating? Bad head gasket? I also replaced my radiator cap with the thermostat. My first step was to buy the right gasket and replace it even though there is no visible leak. Other than that I was gonna see if anyone on here had any ideas????? Help please this is my Daily driver.

[NCReatta]

If you can't see any leaks, and no steam (I.e leaky hose on the exhaust manifold I'm thinking it's somehow getting into the engine and getting "burned" (I.e head gasket).

Have you noticed any loss of power or running rough?

[Barney Eaton]

It is either in the oil, in the exhaust, or on the driveway.

On the driveway is probably the cheapest problem to fix.

Check the oil ....... if water is in the oil it will be overfull and milky

Have you refilled and checked it?

When you refilled how much did it take?

[sfair]

First thought is you got an air lock in the system. Once the water pump starts thrashing coolant around and the thermostat opens, the air lock goes away and poof, the coolant level drops way down. Fill it up and try again.

[Guest spiering.lucas]

Thanks for that last replay stair. My oil is fine and the car runs like a million bucks smooth as a babies bottom and just as powerful as the day it came off the showroom.So my car overheated this morning. And I popped the radiator and it was bone dry. I just did a thermostat on it last week and filled the coolant all the way up? Wtf?

[Guest spiering.lucas]

It took about 4 quarts of water. To much if you ask

Me.

[DAVES89]

4 quarts is too much, especially if you only changed the thermostat. I would bet that one of your hoses are bad and you are leaking antifreeze. If the hoses from the engine to the radiator are "good" then I would take a hard look at the little hose that is at the alternator/water pump area.

It could leak there and you might never notice it.

[Guest spiering.lucas]

Thanks Dave 89 after thero inspection withe the coolant system under full pressure I discovered a small pinhole in the heater core hole along the firewall. Thanks again!