Coolant smell in cabin?

Hi all,

I searched, but I haven’t seen this issue posted here. I left my car parked from Wednesday to Saturday. Upon returning, there was an overwhelming smell of coolant in the car. There wasn’t any coolant under the car, and I can’t find anywhere where the carpet feels damp. The smell was so severe I drove with the window down to let it air out.

I’ve driven it some, there are no error codes, and the smell seems to be dissipating.

Possibly related: the coolant heater was replaced about a month ago. The only thing I can think of is maybe the heater core is leaking? But that’s based on my prior history with ICE vehicles. It only has 15k miles on it, so it seems unlikely the heater core would have failed already.

Any ideas before I book another service appointment?