The engine cooling system of My 1997 Maxima has always worked perfectly. Recently the temperature has started to vary during climbing to altitudes above 5000 ft. The temperature does not reach the high limit but goes to a new setting. Previously the temperature always maintained a constant setting of slightly below midscale even in Phoenix in summer. Can this be a thermostat problem?
The temperature gauge reading could mean a couple things. If the thermostat remains open all the time, then your temperature gauge tends to read on the cool side. If it remains closed all the time then it usually causes overheating.
Remember that in higher altitudes water boils at a different point. Check with your dealer to see if you need to adjust the 50/50 mix of your coolant/water ratio for higher elevations. Maybe the engine is running hotter because of this.
You should also check your coolant level to make sure it's full, as low coolant can cause the engine to run hotter. Of course any blockages in the system can cause higher temperatures also.
Have these things checked out by a technician to properly diagnose this problem. Good luck.
〉 Answered on Nov 26th, 2007 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines