Drive dow street everything is fine then over heating indicated. Shuts down AC compressor. Computer thinks the coolant is at 303 degrees. Always same temp. At same time will have gear selection problem indicated causing no speedometer and no rpm. Will continue for four or five minutes while driving down street with no rpm, no speedometer, no AC, then go back to normal operation. Will continue to go back and forth. Changed temp sensor and checked for air pocket in coolant. Any other ideas?