Hi I have a 2000 Jeep Grand Cherokee, now that warmer weather is here, the temp gauge keeps going up into or close into the red zone. My CarMd says everything checks out ok and there is enough of coolant in my reserve. This also happens when I put the air conditioner on. whats the deal? thx.
It sounds like your thermostat may be failing, it may be sticking closed causing the system to over heat. If you choose to investigate on your own you can remove the thermostat and place in boiling water to see if indeed it is stuck closed. You may need a coolant flush as well, deposits may have formed on the thermostat causing this to happen.
Temperature gauges will vary slightly from season to season and with the use of some components. With warmer weather, your engine may run warmer as there is no cold air around it to disperse the heat. However, if the gauge actually goes into the red or you are experiencing performance problems with the vehicle, this would be an indication that there is a problem and I would suggest you have it checked out.
〉 Answered on May 2nd, 2009 by Suzanne Grego, Technician at City of Philadelphia Fleet Management