QuestionI'm having a high temp issue at high speed(over 55). Thermostat tested okay, fluid level and composition are good, hoses are in good repair and I don't hear any funny noises from the water pump area. I've only seen the passenger side radiator fan running. Should both fans be running when engine is hot and the car is idling?
AnswerFrom what you describe, it sounds like the cooling system actually seems to be working fairly normally. These are the things I think you should do:
1. Doublecheck the operation of the thermostat. Let me know what method you're using to check it.
2. Check the direction the fan blows the air off the radiator. It should pull the air through from front to back.
3. Check the temperature of the air blowing off the radiator when the fan runs. It should be warm or hot. Cool air indicates you have a coolant flow issue, possibly caused by a restricted radiator.
The radiator fans are both controlled by computer. If I recall correctly, the second fan only activates when the a/c is on or the engine temperature gets very hot. To see whether they're both operational, click on the a/c and see if the other fan runs.
