Ok so about 3 months ago I took the jeep to the shop to see why my heater wasn't working. They told me that the heater core was badly clogged and wanted to charge me $1200 to replace it. I declined the repair but asked for a cooling system flush. The temp gauge was a notch below the 200 degree mark after the service.

Figuring I could unclog the feature core my self I did some research and got it cleared out. I then added coolant. Then I started the motor with the radiator cap off and added a little more, maybe a cup or so. The reservoir was topped off. Since then the xj has been running at the 200 degree mark on the gauge. I've since purchased an OBDII scanner and it reads that the temp is between 198 and 203.

So my question is, should I have purged the air from the system and how would I go about doing that?

 

There's a 200 degree mark????????????? Looks like temp is perfect at 198-203. That's about the range our ScanGauge indicated this time of year with a 195 t-stat.

 

^ X2.... Most XJ owners would love to see 200° as most see 210-215°

 

Sorry I think I meant 210 degree mark. Thanks for the replies guys.

 

To get the air out, Park it on a hill so the radiator is up higher then the heater core, remove cap and rev the engine this will push all the air out, also squeeze the hoses to burp it,

 

Most XJ owners probably would see +/-200 this time of year if they used an aftermarket gauge, or scan tool, vs the factory gauge.

 

On your vintage, it is quite efficient of purging any air out on its own within about 3-4 complete heat up / cool down cycles.

The target temp is around 200-210. If you are there, you are okay.

If you want to verify this, get an infrared point and shoot infrared thermometer and point it directly at the thermostat housing.

The reason you want confirmation is that there can be a bit of inaccuracy between the coolant temperature sensor and the gauge.

 

I have been thinking of installing and additional engine and trans temp gauges. Thanks again for the replies guys.