Passenger side is wet, definitely coolant. How hard is it to remove the dash and replace the heater core, or whatever other parts under the dash that might be leaking?
Dealer had part of it out 2 weeks ago, replacing the ignition switch, makes me wonder if they damaged something.
Any mechanics out there who can help?

 

Corroded heater core, $450, got to wonder if GM's fancy coolant is such a good thing after all.

 

how could replceing the ignition switch have anything to do with your heater core??? how many miles on on your Impala?

 

The ignition switch is in the dash directly in front of where the heater core inlet/outlet tubing is, and since the core leaked just days after the ignition switch repair, I figured the mechanic may have damaged it, but that was not the case. The bottom edge of the old heater corewas stained from what must have been a very slow leak that finally got big enough to make the carpet wet.