Similar Problem Temp sensor for gauge. Broke sensor top changing Dis Cap. Changed gauge temp sensor and now reads right below red zone

when you took out old sensor air got into system,now that new one is in you need to bleed the air out of colling system.should be a bleeder valve close to thermostat houseing.

Hello That's interesting. I looked at the therm stat housing which is on the left side and didn't find any thing. Looked at the top rad hose mount casting on the right side of the head where the gauge sensor and a other coolant sensor is and don't see any bleeder. What's interesting is from where the sensor is mounted in the casting it slops up from there by way of top rad hose to the radiator. I would guess from their air would find its way up,and out when thermostat is open and water circulates. I replaced the radiator hoses and stat About 5 weeks ago and all,was fine since then till,I broke,the sensor and replaced it. Years ago I had a ford escort,where the headway above the rad cap and it had a bleeder port in the head to vacate all the air trapped. But I think this is lower than the rad and looks like,it should allow air to travel up. Sc