My car is overheating. I have replaced the thermostat and the water pump, but it still overheats. My coolant reservoir is filled with dirt, and brown stuff keeps shooting out of my radiator. Also, my heater only blows cold air.
You could either have air trapped in your cooling system, or you might have a bad head gasket. Based upon your description, I am leaning towards a bad head gasket. Testing the head gasket can be performed with a block test which pulls vapors from the bubbling coolant and turns the fluid a different color if it detects emissions in the coolant. If you would like to have your AC system inspected by a professional, a certified mechanic from YourMechanic can visit your home or office to diagnose the problem and make the needed repairs.
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