There are multiple sources depending on the production date of the car. Some have had a leaky heater core, coolant expansion tanks are very common, leaky water pumps can be smelled through the air intake, and sometimes, the issue is from the glycol grease that the climate control system/dampers were assembled with.
For starters, sniff around the coolant tank on a hot engine for starters. If you smell coolant vapors there, replace the O-ring on the cap. If you are running your tank near or over the top line the arrow is pointing to, some have found that reducing the coolant level slightly helps alleviate some of the smell/venting as well.
For starters, sniff around the coolant tank on a hot engine for starters. If you smell coolant vapors there, replace the O-ring on the cap. If you are running your tank near or over the top line the arrow is pointing to, some have found that reducing the coolant level slightly helps alleviate some of the smell/venting as well.