There is little to no heat coming out of this E46. First thoughts would be to inspect the thermostat, and heater core valve, as those are typically the most influential pieces that contribute to poor heating.
Other symptoms experienced were the water temperature on the dash was fluctuating, so it was solidified that there is possibly a bad thermostat on the vehicle.
Once replacing the thermostat, and inspecting the heater core valve to see it was clean and in good condition, the system was filled, and bled only to see the car was still not getting proper heating. Confirming the heater core was clean, and free to open and close the valve, the HCV was unplugged to default the valve into the open position. This immediately brought heat into the cabin, confirming that our valve is operational, and our thermostat is cycling coolant correctly through the system, as well as being bled correctly.
The next logical path of correction was to understand how the heater control valve receives its signal. There is a sensor behind the HVAC unit in the cabin, the heater core sensor. If improper signal/temperature is registered, the valve will not open and close correctly not bringing in heat to the cabin. Replacing this sensor solved the problem for this vehicle, and there is full heat in the cabin, under full control of the HVAC unit. Problem solved, and a costly visit to the mechanic averted.
Bonus features of this video, you can reference this on how to remove radio, HVAC/IHKA unit, sunglass holder, and dash trim.
https://youtu.be/YZdGg3qShh4_a_
Other symptoms experienced were the water temperature on the dash was fluctuating, so it was solidified that there is possibly a bad thermostat on the vehicle.
Once replacing the thermostat, and inspecting the heater core valve to see it was clean and in good condition, the system was filled, and bled only to see the car was still not getting proper heating. Confirming the heater core was clean, and free to open and close the valve, the HCV was unplugged to default the valve into the open position. This immediately brought heat into the cabin, confirming that our valve is operational, and our thermostat is cycling coolant correctly through the system, as well as being bled correctly.
The next logical path of correction was to understand how the heater control valve receives its signal. There is a sensor behind the HVAC unit in the cabin, the heater core sensor. If improper signal/temperature is registered, the valve will not open and close correctly not bringing in heat to the cabin. Replacing this sensor solved the problem for this vehicle, and there is full heat in the cabin, under full control of the HVAC unit. Problem solved, and a costly visit to the mechanic averted.
Bonus features of this video, you can reference this on how to remove radio, HVAC/IHKA unit, sunglass holder, and dash trim.
https://youtu.be/YZdGg3qShh4_a_
