foul smell coming from Heating system on 2000 Pontiac Bonneville

When i start the car in the winter time, after cleaning the snow off of it. I return inside and notice a foul smell since the heating system is on It must be the source.
Any suggestion?

Thank you..............captssmarcello

1 answer 1 comment
You may have a leaking heater core or bacteria buildup in the A/C evaporator. The heater core tends to have a "sweet" smell, so I would focus on the A/C. Start by replacing the cabin air filter, if the smell is still there, then take it to an A/C shop that has a machine that will disinfect the A/C evaporator system.
sorry no answer