What are the reasons for slow water temperature rise?
2 Answers
Water temperature rises slowly due to: 1. Thermostat valve closure; 2. Cold weather; 3. Cooling fan malfunction. Solutions for slow water temperature rise include: 1. Replacing the thermostat; 2. Adding antifreeze. The water temperature, detected by the coolant temperature sensor, gradually increases as the engine operates after vehicle startup. The thermostat is positioned on the water inlet pipe of the heat exchanger, serving to maintain a constant water temperature. It continuously monitors the coolant temperature in the engine, keeping the water temperature around 80 to 90 degrees Celsius to ensure optimal engine operating conditions.
After decades of driving, I've found several main reasons for slow engine temperature rise. The most common is a thermostat stuck in the open position, causing coolant to prematurely enter the major circulation loop, allowing engine heat to dissipate too quickly and preventing proper warm-up. Other causes include faulty or improperly set cooling fans running at high speed continuously; insufficient or aged/contaminated coolant with poor heat transfer efficiency; or a worn water pump impeding proper coolant flow. Naturally, temperatures rise slower in cold weather, but always check antifreeze concentration to prevent freezing. Additionally, internal engine carbon buildup or cylinder head gasket issues can hinder warm-up. Low coolant temperature increases engine wear and emissions, while prolonged preheating wastes fuel. I recommend regular coolant changes and thermostat inspections to prevent minor issues from escalating. If problems arise, visit a professional shop early for proper diagnosis.
