What is the reason why the new thermostat won't open?

[Coleman]

Reasons why the new thermostat won't open: 1. Internal damage to the thermostat; 2. Damage to the thermostat opening valve; 3. The water temperature is too low. The thermostat is a valve that controls the flow path of the coolant, serving as an automatic temperature-regulating device. It typically contains a temperature-sensing component that uses thermal expansion or contraction to open or close the flow of air, gas, or liquid. The thermostat usually includes a temperature-sensing element that relies on expansion or contraction to open or close the coolant flow, automatically adjusting the amount of water entering the radiator based on the temperature of the coolant. This changes the circulation range of the coolant to regulate the cooling system's heat dissipation capacity. Currently, the most commonly used thermostats are wax-type thermostats, which control the coolant circulation method through the thermal expansion and contraction principle of the internal paraffin wax.

[EmersonMarie]

Having played with cars for years, I've encountered quite a few cases where new thermostats fail to open. Most often, it's due to installation errors—like mounting it backward. The thermostat has an arrow mark that should face the coolant flow direction; if installed wrong, it'll definitely get stuck closed. Another possibility is getting a defective unit where internal debris from manufacturing blocks it, causing delayed opening. Additionally, air bubbles trapped in the cooling system can hinder operation—when the engine heats up, these bubbles obstruct fluid flow, preventing the thermostat from opening. The solution is straightforward: First, verify proper installation by checking the arrow direction after removal. If correct, inspect the system for air leaks and bleed it using the vent valve. If all else fails, replace it with a reputable brand—I recommend avoiding cheap options since this component affects engine health. Chronic overheating could damage cylinder blocks, costing thousands in repairs. Address it promptly for safety.

[EmeryAnn]

After replacing the thermostat, I was really worried when it didn't fire up properly. The engine temperature rose too quickly, and the fan kept spinning like crazy. After consulting friends, I learned there are two common causes: either the thermostat was installed crooked or the screws weren't tightened properly, causing leaks and air intake, or the thermostat itself was of poor quality and got stuck internally. I tried starting the car and observed the temperature gauge—if it didn't cool down after passing the normal 90 degrees, it indicated a problem. Then, I checked if the coolant was circulating smoothly, as sometimes clogged hoses can hinder heat transfer. A simple fix is to bleed air bubbles and ensure all connections are sealed. I figured that leaving this issue unresolved would affect fuel consumption and power, and over time, the engine could overheat and fail faster. So, it's better to buy parts from reliable sources as a preventive measure.

[DeValeria]

A new thermostat failing to open is usually caused by incorrect installation or component defects, such as the thermostat being installed upside down blocking water flow, or being stuck from the factory preventing the valve from opening to cool the engine. Air bubbles in the system are also a contributing factor, as trapped bubbles hinder heat exchange and render the thermostat ineffective. Solutions include rechecking the installation position and performing a bleeding operation to ensure smooth flow. Ignoring this issue may lead to engine overheating and damage to core components.

[DelHarrison]

I've encountered situations where a new thermostat fails to open, mainly due to quality or installation issues, such as purchasing cheap parts with internal springs rusted shut. Additionally, aged coolant generating air bubbles can interfere with the thermostat's operation, causing the engine to overheat and trigger warnings. The solution involves readjusting the installation position and bleeding the air. Ignoring such faults can easily lead to engine deformation, seal leaks, and increased costs, so timely maintenance is crucial for safety.