My cars making a squealing noise when cold and at low rpms. What can i do to make this stop ?

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. The clue here is that the noise occurs with the heating on. You might not think about this, but when the heat is on it means the air conditioning compressor is typically operating - creating a load on the accessory drive pulleys. The compressor operates to dehumidify the interior even though you are looking for heat and not cold air. The clue is that when there is a load on the accessory drive pulleys that the belt is riding on, a squealing noise is heard. This would lead me to believe that the belt needs to be replaced, a belt tensioner may be binding, the idler pulley may be binding, or the air conditioning compressor itself is possibly failing. Have a tech near you check this out. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.