The temp sender at the block works fine until the temp reaches 180F, then it sends a very high temp (240 or higher) and fluctuates.
I've checked the sender resistance and it checks out, so I don't think it's the gauge. I've cleaned the threads as best I could at the sender and block. The sensor at the thermostat is reading steadily around 190 once the thermostat opens, which I've confirmed with an IR thermometer. The top radiator hose is warm, the bottom hose is cold.
Air has been bled and no boiling or coolant overflow or any other signs of overheating. I checked cooling system pressure and it holds. Car runs and idles great.
I just want to make sure this isn't a coolant circulation issue before I replace the sender. When pointing the IR thermometer at the head near the sender, it reads more or less the same temp that the sender is sending. It seems that it's sending the head temp instead of the coolant temp, which I believe should be lower due to pressure and circulation.
Is my reasoning sound?
I've checked the sender resistance and it checks out, so I don't think it's the gauge. I've cleaned the threads as best I could at the sender and block. The sensor at the thermostat is reading steadily around 190 once the thermostat opens, which I've confirmed with an IR thermometer. The top radiator hose is warm, the bottom hose is cold.
Air has been bled and no boiling or coolant overflow or any other signs of overheating. I checked cooling system pressure and it holds. Car runs and idles great.
I just want to make sure this isn't a coolant circulation issue before I replace the sender. When pointing the IR thermometer at the head near the sender, it reads more or less the same temp that the sender is sending. It seems that it's sending the head temp instead of the coolant temp, which I believe should be lower due to pressure and circulation.
Is my reasoning sound?
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