I barely go half a mile and tahoe overheats. On dash it says coolant to hot.. and loses power.. chamge thermostat twice, coolant temp sensor and water pump. Could it be a bad cluster or a computer problem. No codes or chk engine light. I also flushed system and put new coolant in. Is the radiator plugged? Fans are working efficiently. If someone has a clue and can reply asap but much appreciated