Why is the automatic exhaust valve continuously draining water?
4 Answers
Automatic exhaust valve continuously draining water is a malfunction caused by damage to the automatic exhaust valve device, resulting in water discharge instead of gas exhaust. Solution: If the issue is caused by a damaged automatic exhaust valve, simply replacing the automatic exhaust valve in a timely manner can resolve the problem of water discharge without gas exhaust. Working principle of the automatic exhaust valve: When the system is filled with water, gases in the water continuously escape and accumulate at the highest point due to changes in temperature and pressure. When the gas pressure exceeds the system pressure, the float drops, driving the valve stem downward to open the valve port, allowing continuous gas discharge.
I think the automatic exhaust valve continuously draining water may be due to aging or damage of the internal sealing ring. When the cooling system is functioning normally, the exhaust valve only briefly releases air when the system pressure is too high, helping to expel air bubbles to prevent overheating. However, if the valve is stuck or the spring fails, it will continuously leak water, leading to coolant loss. During inspection, you can first check if the drainage outlet feels hot and damp, and combine this with the dashboard coolant temperature indicator to assess the system's condition. It is recommended to visit a professional repair shop to replace the valve as soon as possible. Otherwise, engine overheating can damage the cylinder head, resulting in higher repair costs. I have dealt with a similar issue myself, and delaying repairs can cause the car to break down on the highway.
Speaking of the exhaust valve frequently leaking water, my SUV has had this issue a few times. At first, I thought it was normal, but later I got worried when I noticed the coolant reservoir level dropping rapidly. Possible causes include air trapped in the system causing pressure fluctuations, or the valve being dirty and clogged. I tried adding water for a quick test but didn’t dare to attempt deeper repairs since I’m not a professional. It’s best to get it fixed promptly and have the technician inspect this component during routine maintenance—it saves both money and hassle. I remember after the last repair, the vehicle ran much quieter.
Over the years of driving, continuous water drainage from the exhaust valve usually indicates wear of the valve components or loose connections causing air leakage. Key inspection points: Ensure the coolant is filled to the standard level when the engine is cold; observe the drainage situation after operation to see if it changes with temperature. If it keeps dripping, it's mostly a fault, and the valve body needs to be replaced to avoid cooling system failure. It's safer to have an experienced mechanic handle this. Ignoring this issue may trigger an engine high-temperature alarm. I recommend regular maintenance to prevent such problems.
