Do a complete charging system test and verify the alternator output is in range. Did the voltage come back up with the new battery?
We know that the temperature isn't going to "actually" drop 50 degrees in an instant. So obviously there is a continuity or component malfunction. You can verify this with a scan tool connected to the vehicle at operating temperature. There is an Engine Coolant Temperature sensor for the PCM and a Temperature Sending unit for the gauge.
If the scan tool displays 200-210 we know it's the sender to gauge circuit, the sender or the gauge.
Tuesday, January 26th, 2010 AT 4:49 PM