car starts and runs no odors but have coolant under dash on passenger floor

Make sure the coolant level stays full. This needs repaired. It will continue to get worse, the fumes from coolant are not good for you, the steam will coat the glass and make it hard to see.

If you have ruled out the heater core as being the problem, the water leaking on the passenger side under the dash is caused by a faulty design of a rubber cover placed over the HVAC unit.

What you need to do is remove the cowl & then you will have access to the covering over the HVAC unit.

You can either construct a new covering or contact Chevrolet to see if they have a replacement one. Also, be sure to clean the area thoroughly & use a good waterproof sealer.