Q: How to replace a thermostat in a cooling system?
A: To address cooling issues, first inspect the coolant level, drivebelt, and temperature gauge. A slow-warming engine suggests an open thermostat, while an overheated engine with a cool upper radiator hose indicates a closed thermostat. Avoid running vehicles without thermostats due to emission and fuel concerns. For thermostat replacement: disconnect the battery, drain the cooling system, and access the thermostat via the upper radiator hose. Detach the hose, and, depending on the engine, possibly relieve fuel pressure or remove heater brackets. Remove the thermostat cover and old thermostat. Clean the surfaces, replace the gasket or use RTV sealant as needed, and install the new thermostat. Reconnect components, refill and bleed the cooling system. Run the engine, ensuring no leaks and correct thermostat function.