1997 Pontiac Sunfire
2.2L Automatic
89,000 Miles
Coolant Flush within last 20,000 miles
So my Sunfire has been having a really weird overheating issue lately, so maybe someone can help me figure out what's going on so I don't go replacing parts that aren't the issue.
The car likes to overheat in cooler weather, as I don't think I have had this problem during the Texas heat in the summer. It's been in the 30's recently, I have notice the issue almost everyday now.
The car is lossing coolant, but I really can't tell how because I haven't seen any real leaks or pools of coolant under the car. My coolant light is constantly coming on, but sometimes it goes away. Of course, I add coolant every so often.
The car really starts to overheat after being on the freeway for about 15-20 minutes. The guage will move it's way up to right before the red, then stay pretty constant. It never hits the red. Sometimes it goes down on it's own, other times it stays right where it is.
The weird thing I have noticed is that although my AC or Heater is OFF, I can adjust the temperature knob for the climate control toward the coldest setting and the temperature will quickly begin to drop into the "normal" range. If I leave it on the coldest setting, the car's temperature is just fine.
If I move the knob back to the hottest setting, the temperature begins to creep back up and stops right before the red.
Does this sound odd to anyone? What could be the problem?
I noticed my primary radiator fan takes a while to kick on while driving in the city or idling, but this shouldn't matter on the freeway.
I also noticed that if the car was fine temp wise on the freeway and I exit and pull into a drive through or something, the car starts to get hotter while idling sometimes. It only really happens coming straight off the freeway.
If anyone could help me figure this out, I'd greatly appreciate it!
Thanks!
1997 Pontiac Sunfire
Did you burp the system after changing the coolant? On the black pipe that runs along the top of the engine, there is a small hex screw that you use to get excess air out of the system. You may not be loosing coolant, but might have an air pocket somewhere that is slowly getting pushed out.
Kardain wrote:Did you burp the system after changing the coolant? On the black pipe that runs along the top of the engine, there is a small hex screw that you use to get excess air out of the system. You may not be loosing coolant, but might have an air pocket somewhere that is slowly getting pushed out.
I had the coolant flushed and filled at a shop with the actual machine to do it. I doubt it's simply pushing out air pockets.
What would explain the temperature's reaction to the climate control knob even when the climate control is off?
1997 Pontiac Sunfire
Quote:
I also noticed that if the car was fine temp wise on the freeway and I exit and pull into a drive through or something, the car starts to get hotter while idling sometimes.
This is normal. As long as there is air flow through the radiator, there is no need for the electric cooling fan to be on. Idling it will have a need to come on after some time.
Only other thing I can think of is a blocked heater core.
