When the a/c is on, it smells like antifreeze coolant and has a fishy/musty smell. No leaks in the right floor board. The a/c has a hard time cooling and has excessive evaporator drainage. We’re thinking the fishy/musty smell may be the heater core, but the coolant has stumped us. We replaced a bad radiator cap after it leaked 6 months ago. Oil also seems to be disappearing. There are no oil stains on the ground and no smoking.