2019 XJL port.
I just got the car shipped from FL to LA less than 2 weeks ago. Every time I start it that warning pops up. I filled the coolant level fluid to the top line when vehicle is cold. The warning still come on. I contacted the sales person and he says drive it for 45 minutes to get the air out of the system and it will go out. I smell BS. I know it's probable the sensor so I think they should pay for it on the 30 day warranty. I'm basically left with the bag, I mean Cat. Any advise?

 

I believe there’s a bleeder on the passenger side of the engine bay back near the firewall (at least there is in my 2015). Wait for the car to be cool, crack that bleeder open or off and top off your tank until coolant comes out the bleeder and then lock the cap down. If it’s still reading low at that point the coolant tank level sensor has likely crapped the bed.

 

The sensor is definitely in the coolant reservoir (the one with the cap on it), so if the fluid isn't low in the coolant reservoir, but you are getting a low level light, then no amount of burping or bleeding the coolant system is going to fix the low level light. The sensors are a known weak point on these cars. It's not that big of a deal to put on a new coolant reservoir that has a new sensor built in. I am sure you will find plenty of threads on here and youtube videos to show you what is involved.

 

Yup, I had my tank replaced due to a bad sensor. 2019 with only 20,000 miles at the time.

 

There are two things that the coolant level sensor in the tank floats. First there must be the proper coolant to water ratio of 50% is present or the sensor is bad.

 

I used waterless coolant (ratio of 0% water to coolant) and my coolant reservoir sensors work fine.

 

Hope you realis THE 50/50 IS WHAT THE SYSTEM EXPECTS. using 100% will not cool the engine properly.

 

Well, that's a very definitive statement. You must be extremely knowledgeable about engine cooling systems.

So tell me, what do you think would happen if you switched to waterless coolant that is 100% glycol in a JLR Supercharged 3.0L gas engine that is in a heavy 2014 Range Rover Sport 4WD that already had 50K miles on it and drove it for 100K miles in stop and go traffic in brutal over 100deg F South Texas weather during the summers and at times below freezing during the winter, and did this on the original water pump and coolant pipes with no coolant leaks whatsoever? Based on all your knowledge of cooling systems, what are you saying would happen to the engine?? How would an oil analysis look? Would it smoke out the tail pipe? Would it run rough? Would it be way down on power?

 

XJsss:
Lotusespritse do use special coolant what does not have water at all. Not unmixed std coolant fluid. Yes: Using unmixed std coolant is not very good, its better than no coolant at all though.

 

These engines are designed for 50/50% orange anti freeze and distilled water combo. The Orange anti freeze is formulated for Jaguars aluminum engines and are to best for heat transfer.. and is what the techs at my jaguar dealership used and recommended.

 

Yes, to be more precise: Motorcraft WSS M97B44-D (x351 engine is made by Ford)
Most vehicles, including x351 XJ:s, are running 50/50 water based coolant mixture even extreme conditions like middle east without issues.
However: I understand if somebody like to test alternatives.
(i used to race and had to find a way to run engines on their max with just plain water - no other was allowed on track)

 

I bought some antifreeze for Jaguars but it's red. Is it OK to add that into the orange stuff?

 

No! do not mix. Go buy the correct orange coolant for your your x(351) model. And get distilled water to mix it 50/50.

 

You think if I get a long bar spoon, stick it into the tank and stir, will make the sensor float? LOL I'm kidding.

 

Yes, I was able to lift the float using a stiff wire hook.

 

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