Common problems with car radiator thermostats 

When it comes to your engine cooling system, the thermostat is a crucial component. This helps to regulate the temperature of the engine coolant by controlling the flow of coolant between the engine and the radiator. A functioning thermostat can ensure that the engine operates within its optimal temperature range. However, if this malfunctions, there are a number of issues that can occur. So what are the most common problems with car radiator thermostats? And how can these problems be resolved?

So what are the most common problems with car radiator thermostats?

There are a number of problems that car radiator thermostats can experience, including:

  • Thermostat failure
  • Housing leaks
  • Clogging
  • Electrical issues

Thermostat failure

The main problem that can occur with any thermostat is thermostat failure. This is when the vehicle thermostat becomes stuck in either the open or closed position, leading to improper engine temperature regulation. When stuck open, the engine may take longer to warm up, resulting in reduced fuel efficiency and increased emissions.On the other hand, if the thermostat is stuck in the closed position, the engine may overheat, potentially causing severe damage. Thermostat failure is often a result of wear and tear, corrosion, or the accumulation of debris within the thermostat mechanism.

Housing leaks

The thermostat housing is a component that connects the thermostat to the engine block, and provides safe “housing”. However, this can degrade over time, which can cause coolant leaks. These leaks can result in a loss of coolant, which can cause the engine to overheat and potentially lead to engine damage if not addressed promptly. Additionally, coolant leaks can pose a safety hazard if the coolant drips onto hot engine components, causing steam or even fires.


Clogging is another common issue with car radiator thermostats. Over time, contaminants such as rust, scale, and other debris can accumulate within the cooling system, including the thermostat housing and the thermostat itself. This buildup can restrict coolant flow, leading to inefficient engine cooling and potential overheating. Clogging can also prevent the thermostat from opening or closing properly, further exacerbating temperature regulation problems.

Electrical issues and car radiator thermostats

Finally, electrical issues can affect the performance of electronic thermostats. Modern vehicles often use electronic thermostats that are controlled by the engine’s computer system. If there is a fault in the electrical circuitry or a malfunction in the engine control module (ECM), the thermostat may fail to operate correctly. This can result in erratic temperature fluctuations or the thermostat remaining stuck in a single position, causing engine performance issues and potentially triggering warning lights on the dashboard.

Here at MRS Heat Transfer we are radiator, car heater, intercooler, and air conditioning experts, and we have the skills, knowledge and expertise to resolve any air conditioning or car heater problem. Why not get in touch today to find out more?