Filled up coolant but it dropped back down in about a month

[reddeffect]

Am I looked at needing to replace the head gasket soon? How soon should I do it? 03 baja 110k miles

[kamesama980]

Failed HG is certainly possible but there are other, easier, possibilities to rule out first (since the EJ HG usually leaks oil long before losing coolant): leaking radiator (which can be nefarious since as it dribbles down the core it gets blown away), heater core, various hoses

[anarchy1024]

Look around the engine bay, and if you see some white crusty residue, it could be evidence of a coolant leak. There are also coolant lines that go into the throttle body, for example, so don't only check around the radiator.

[jdlmodelt]

leaking water pump, leaking coolant hoses, leaking heater hoses, leaking gasket on thermostat (check this, another manufacturer's thermostat housing has an "O" ring that fails and the coolant leaks out very slowly like yours.

[jdlmodelt]

leaking water pump, leaking coolant hoses, leaking heater hoses, leaking gasket on thermostat (check this, another manufacturer's thermostat housing has an "O" ring that fails and the coolant leaks out very slowly like yours.