Cleaning water jackets 225

The car was running for about 15-20 minutes. The needle was 1 line from the end of the gauge. It was pouring here in NJ and the Dart doesn't go out in the rain, lol. I will see what my numbers are once I get it out on the road. Thanks to all checking in. I will get the new sensor to see what that does.

Thank you all so much.
Top end of the gauge or bottom end? If top end, then, yes, the sensor, limiter, or gauge is off; it ideally would be around 1/3 up from the bottom in the normal with that level of temps. One other check you can do is to read the sensor resistance (sensor connection to sensor body) at a given temp; at 175 degrees on the t'stat housing measured with a temp gun (which is maybe 180-185 in the top front of the head), then the sensor resistance should be in the 20-25 ohm range.

If you change the sensor, and it still reads hot as before, then either the gauge or the voltage limiter is off.

How accurately does the fuel gauge read? If it reads consistently high across all fuel levels, then the limiter is likely off.