Smell antifreeze after driving. Don’t notice any leaks or using any but I smell it after parking back in the garage.
Could be the heater core. Check for damp carpet under the dash.
Is the coolant disappearing? In other words, is the coolant reservoir still full?
Try replacing the radiator cap.
The radiator cap may be weak and is allowing coolant to escape as a vapor.
Tester
Is this a new problem or an old one? When did you first notice it? Do you only smell it in the cabin or also under the hood? Do you notice it more when running heat with fan? Fumes can drift from engine compartment into cabin, but If only in cabin check the heater core. When running the defroster does an oily residue build up on the inside of the windshield? It’s not healthy to breath, so don’t ignore it.
You don’t smell it at all inside the car just when you get out. This vehicle only has 50,000 miles. I don’t really run the heater much. This vehicle sits in the garage most of the time because it’s the wife’s. We only drive it on the weekend.
Many years ago, I had the same problem, and I finally figured out that the screw-clamp on the upper radiator hose was just… slightly… loose. The amount of antifreeze that escaped was so small that it evaporated quickly, but the odor remained. So… check those hose clamps, on both the radiator hoses and the heater hoses.