2004 XJ8 with 145K Miles

I noticed my Radiator Fan was no longer working lass Fall. Since I live in a northern climate I deferred this job. I recently purchased a used radiator Fan off of EBAY and confirmed it was working. I installed the fan with no issues. When I began to fill the radiator I had a number of air bubbles that needed to be released. As a result, the engine ran hotter and the fan kicked on. After adding coolant a number of times I was able to eliminate any trapped air and the cooling system seems to be working fine. Note, I also replaced my hoses and thermostat housing as well. What I have noticed is that the fan is not coming on. This is with temperatures in the mid-80s. My temperature gauge always seems to stay right in the middle. Again the only time I saw the fan come on was when I had pockets of air and it registered higher than normal. Also I thought when you ran the A/C that would automatically kick on the radiator fans as well. I would appreciate anyone's informed thoughts on this matter. Thank you.

 

Do not use the instrument cluster gauge to monitor coolant temperature. The gauge does not change from 96 C to 129 C, which may be too late to avoid an overheating situation.

Use the Torque app on a smartphone and connect to the PCM via the OBD port with a Bluetooth interface to monitor real-time coolant temperature. The radiator fan speed and cycle is controlled by the PCM.

 

Thank you NBCat. I had not realized that this technology had become so affordable. Have a Blue Tooth enabled OBD ordered and looking forward to seeing what it tells me. Thanks again.