What Causes the Abnormal Noise in Car Heating?

[ORobert]

Here are the reasons related to abnormal noise in the heating system: Uneven water flow or debris in the heater core: This is mainly caused by uneven water flow or debris being washed inside the heater core. One reason could be residue left during welding or blocked covers, or sand and impurities entering the heater core from the heating system and settling, which then produce noise when washed by water flow. If the interface between the heating system and the heater core is not smooth, or if the heating valve is not fully opened or opened too narrowly, the valve may produce noise, which could also cause the heating water to impact the pipe walls of the heater core, resulting in abnormal sounds. Noise may also occur when the inflow and return water volumes are unbalanced. Solutions for noise in the heater core: You can try adjusting it yourself. First, close both the inlet and return valves of the heater core completely—ensure the return valve is tightly closed. Then, open the inlet valve and release the air from the air vent at the top of the heater core. After all the air is released, close the air vent and slowly turn the return valve open. If noise appears, adjust it back slightly until the noise disappears. If noise persists no matter how you adjust the return valve, fully open the return valve and adjust the supply valve instead. If noise still persists, slightly close one valve and adjust the other until the noise stops.

[VanAsher]

I'm someone who enjoys troubleshooting car issues. Last time I encountered strange noises from the heater, it took me a while to figure out the cause. Accumulated dust or leaves stuck in the fan blades is common, causing a buzzing sound when rotating; if there are air bubbles in the pipes, the water flow gets blocked, resulting in a gurgling sound; worn-out water pump bearings produce a squeaking noise, and a loose or dry air conditioning compressor belt can do the same, potentially damaging other components over time. It's advisable to stop using the heater first, check if the coolant level is low, or bleed the air from the system. Try cleaning the filter yourself, but if that doesn't work, it's best to have a professional shop inspect it. Don't ignore small issues that could turn into big problems.

[LaJosie]

The strange noise when the heater is turned on is quite annoying and also related to driving safety. If the fan motor is about to fail and stops rotating, the engine compartment may overheat, posing a fire risk. A bubbling sound from pipe leaks indicates a problem with the cooling system, and failing to repair it promptly can lead to uncontrolled engine temperature. I would first check if the dashboard water temperature is normal, then turn off the heater to listen for the source of the noise. If it's a squealing belt, it might be due to lack of lubrication. Remind everyone to perform more maintenance before using the car in winter, ensure sufficient antifreeze is added, and don’t delay repairs when strange noises appear, ensuring a safe and worry-free journey.

[PiperDella]

As a new car owner, I've also encountered strange noises from the heater. Simply put, it could be something like a small stone stuck in the fan blades, causing a rattling sound when rotating - just clean it and the noise will disappear. Or there might be air in the system making gurgling sounds, which can be fixed by bleeding the air. Issues with the water pump or compressor are slightly more complicated, but don't panic - most of the time these noises don't affect driving. However, I've learned not to delay addressing them to avoid major repairs later. First, check if the filter is dirty and try replacing it with a new one. If you really can't figure it out, consult a car-savvy friend or visit a repair shop.