Engine Cooling problem
2003 Infiniti G35 6 cyl Two Wheel Drive Automatic 192000 miles
On warm days (usually over 80 degrees) my engine will begin to overheat when I am sitting in traffic. If I turn off the A/C the temp will stabilize and I can keep within the operating range but it is on the High end of the scale. If I turn the A/C back on the temp will begin to rise. I don't notice this as much on the open highway but if the outside temp is up over 90, the engine temp will push up to the high side of the scale even in highway driving. Turning off the A/C is the only way to keep within the operating range. When I am sitting in traffic at a red light, I can here the fans kick on so I am pretty sure the fans are operating when called for. I have had the coolant checked at Infiniti and they are telling me it checks OK. Would the Thermostat be the problem?
There are a few possible causes for the problem : 1. Cooling fan. The cooling fan operates at different speed for cooling and if it is not working at the highest speed when the temperature is high, the efficiency is insufficient. However this would not be a likely cause as at cruising speed the moving air should be able to cool the radiator to lower the temperature reading.
2. Radiator partially clogged. If the radiator is clooged partially, cooling efficiency would be reduced causing high temperature reading. When this occurs, the higher the speed the higher would the be temperature reading.
3. Bad thermostat. It could be stuck in partially open position resulting in reduced coolant movement that would cause the temperature to rise.
4. Insufficient coolant. When engine is cold, remove the radiator cap and check if the coolant level is at the neck. Check the reserve tank coolant level.
5. Bad water pump. This would reduce the coolant flow efficiancy.
From the above, item 2 and 3 would be the most probable cause.
August, 4, 2010 AT 9:01 PM
Did you ever fix it I am having the same exact problem?