Has anyone any experience with coolant temperature sensors please. How do they usually fail: open circuit or short circuit, or do they become inaccurate as they warm up and would a resistance of 2KOhm be reasonable at room temperature? It's a (A 099 905 37 00). Just trying to figure out why my temp gauge has started rising much slower than usual, indicating that the engine is taking a longer time to warm up, even in the high temperatures we've been having recently. Don't think it's the thermostat as the radiator to thermostat hose stays cold until the gauge reads over 80 degrees.