runs warmer than normal at idle

Hello, If raising the engine speed slightly while stopped fixes the issue, you likely have a leak or clog in the system. If raising the idle while stopped does not fix the leak, you likely have a bad water pump or a clog in the system. The best place to start is pressure testing the system and the radiator/overflow cap. This will let you know if a leak is present as well. If no leaks are present and the engine cools when you raise the engine speed with the vehicle in park, run a detergent (cooling system flush) through the engine with the thermostat out. Also, ensure you are properly burping the system to remove air. If there is air in the system, it will never stay cool.