I took my Jag for a spin this morning. After going on the interstate for 15 miles, I turned around and went home for a total of 30 miles. About 8 miles from home I turned the air conditioning on for the first time this year. When I was about 3 miles from the low coolant level message/yellow light came on. I got home and let it cool for about 30 minutes. Then I slowly and carefully removed the coolant cap to check the coolant level. The manual recommends the level being even with the filler neck when COLD. When I checked it while being between warm and hot, the level was about an inch from the bottom of the filler neck. Would this be enough to prompt the low coolant level message/light to come on? I didn't think that turning the air on for the first time this year would be related, but I thought I should mention it. There was no coolant in the floor upon returning home, but there was a lot of condensation dripping at the back of the engine. Thanks for your advice, Louis

 

Sounds like you may have a small slit in one of the heater hoses at rear of engine. Did you smell odor of antifreeze? Had that happen to me.

Good luck

 

My coolant light is also very quick to come on - not such a bad thing, but it can be alarming. It usually needs just a pint or so of fluid when it does. I am in a hot place and drive everyday but add a little coolant only every month or so between changes.

 

Thanks FYRPlug. No, I don't smell or see any antifreeze.

 

jaginblack, it was hot already this morning when I drove it. It's around 90 degrees here now in Southern Illinois. I'm glad to know it's quick to come on, and the fact that you have to add some coolant occasionally. Yes, it definitely alarmed me! Thank you for your input. FYRPLG also indicated it could be a slit hose. Even though it isn't this time, I will keep an eye out for it. Thank you both, Louis

 

The low coolant light will go off way before the tank is empty and driving over any bumps can turn it "on" if the level is down a bit.

When was the last time you checked it? Has the coolant been changed recently?


I would fill it up with the correct coolant and check it in a few days.


It is not normal to have to add coolant on a regular basis - if it is dropping you need to find out what is up.

 

yeldogt, thanks for responding. I did indeed repair the heater valve hose a couple of months ago. This is the first time the message/amber light came on since. I lost a lot of coolant at the time this hose blew, and it's possible I didn't completely fill it to the bottom of the filler neck while it was cold. It's now filled, and I drove it last night. The light/message were off upon starting, so I'll check the level in a few days to see if it's okay.

 

The tank holds a fair amount of fluid. It's bigger than it looks - so when empty you have lost a significant amount of fluid.


Normally, after servicing the cooling system it requires a top off -- some air always seems to get stuck someplace. Hopefully, that is your situation and all will be fine - that is why I asked if you did any servicing.


My car is an 02 -- I have only added coolant once in all that time. Other than fluid changes.

 

It came on in my Sovereign once, the level is a bit below the expansion tank neck
Topped it up, not happened since

 

BS at 11, thank you as well. I was able to get a total of 20 ounces in it. Hopefully, it was needing a bit from the hose change I completed earlier this year.

 

I was startled when I first got my 02 Jag XJ8 (about 4 years ago) to learn how sensitive the low coolant sensor is. Mine got my attention when it came on; coolant tank looked just a little low but not much. Added no more than a pint: No further warnings! Once about two years ago I had to park on a really steep incline. The low coolant light came on when I later started the car; as soon as I got on a level street the light went off!

I would guess from these experiences that you don't have a problem.

 

This adding of coolant first began after I blew the norma connector some time back on the infamous heater hose matrix that has all the connections. I lost a lot of coolant. I filled it at the header tank, and turned the heat on, etc. to fill the system. Even though I didn't actually change my coolant, I was on the JTIS a while ago looking at the procedure for changing coolant. It talks about: removing the threaded plug and dowty washer from the charge air cooler fill point, and then filling the cooling system at the header tank until the level stabilizes at the top of the charge air cooler fill point. I failed to do this when I cut off the norma connector portion and hose-clamped it to the pipe. I am now wondering if maybe since I didn't follow this procedure for changing, since I lost a lot of coolant, if this is why it appears to be "using or leaking" coolant. I see no coolant on the ground, nor do I smell any coolant. Maybe I have never gotten the system full, since I didn't remove the charge air cooler fill point plug. I just wanted to ask if anyone thinks this is a possibility. Has anyone heard of this at all? I was going to maybe purchase some allen wrenches to remove the plug and do the procedure for changing coolant since I did lose a lot. Thanks for your help, Louis

 

That size of allen wrench is hard to come by.

A bolt with a 19mm head and two matching nuts is easier to get. You don't need a long one, 40mm will do just fine.

Thread both nuts on the bolt, jam the two nuts together by turning them against each other.
ie. loosen the inner one while tightening the outer one.

Put the bolt head in the plug and turn the other end with .... you guessed it, a 19mm socket.