Hi I'm Jessica or Gypsy 😏 so almost 2 weeks ago I finally got my hands on a Jag. I was told she had a small coolant leak, he had kinda repaired it, new o-ring but added some orange silicone. Had no issues during the test drive. Once I got to highway speeds ( I was going 50-55) she started overheating. Stopped first time had to send daughter to get antifreeze. Yes I checked before my test drive there was water in the reservoir. Anyways, get antifreeze back into the system and she runs fine. After about 4 miles she started heating up again.
Stopped again, shut her off, FANS KEPT RUNNING, popped the hood, from the backside of the thermostat Housing Assembly I had hit air escaping from where he said he had fixed, but still had coolant in over flow. Fans shut off after a few minutes, and then the hissing stops as well. After a few minutes I start her back up and get going again, doing okay again starts to heat up. I hit town and slow down below 50, she starts cooling off, and runs just fine in town at 30-35.
Get her home, and yes she sat for a week until the new housing assembly showed up, which was today. I have just finished replacing the housing assembly BUT, I had to get creative since the new housing assembly some of the hose nozzles were in different areas and I believe , the sensor on the front driver side, was moved to the backside facing towards the engine instead. Anyways, I had to ADD wire to my plug to make it longer so I could plug it in. And one of the front smaller nozzles was moved more towards the drivers side, so I had to also extend one of my hoses.
After everything was put back together, turned her over, started up. Let her sit and idle for a bit, no issues. Got out my reader and got a code for the Fuel temperature sensor... I know what the part is, looked it up, and it looks the sensor that's on the housing assembly, that I had to extend my plug wires just to plug it back in...

So my question is the sensor on the thermostat Housing Assembly, is that the fuel temperature sensor? Or No? And if No, where the heck is it? Because I've tried looking up where it is and how to replace, and I get nothing for it.

Kinda hard to see but the orange silicone is where antifreeze leak was. As well as the hot air ,when she was over heated, not in the red.

Kinda hard to see, but the orange is the location

 

Very thorough write up. The fuel temp sensor is on the fuel rail somewhere not a part of the coolant system at all. It is hard to see on the photos what you are pointing out. If you use the jaguar parts catalog via jaguarlandroverclassic.com then go to fuel system and it will show the temp sender and its location. Keep forging ahead you are doing great. It looks like the temp sender is on passenger side at the back of the fuel rail. That would be away from the housing you replaced i think