On my 2005 XK8 There is a red light at the top of the temp. gage that comes on when cold engine is started and goes off every once in a while, while driving. It is full of coolant. What is this telling me? Bad connection hopefully.

Thanks
Jack

 

Have you hooked up an OBD-II scan tool to see what the actual coolant temperature is at any given moment ?

That would be my suggestion to do first, just in case there is actually something strange going on. Once that worry is behind you, you can start checking the sensors and wiring.

Z

 

Thanks Z. I'll have my son do that next week. I was stuck in traffic 80 deg F today for a while with no ill effects. But I will check as you said

Thanks
Jack

 

Have a look at this thread and confirm which red light you are talking about:-

https://www.jaguarforums.com/forum/x...solved-188018/

 

Thanks for the link dibbit. The light that I am talking about is the rectangular light just to the right of the (H) on the gage between the 2 upermost marks on the scale. I haven't found anyting telling me what this light is for. I know it's not telling me my engine is hot because it is on when the engine is cold. When first cranked.

Thanks
Jack

 

I believe your sensor and / or wiring is at fault as that is the light to indicate overheating .


Z

PS: section 3-3 of the Drivers Handbook indicates any red light within the instrument dials are for “primary warnings” . Which I take to be associated with the adjacent gauge. Which in your case is the temp gauge.

 

Thanks again zray. I'll check it out.

Jack

 

That isn't a warning light, its just the red segment of the gauge, all of which is backlit and can make it look like that top red segment is lit up. The warning light is top right and not part of the scale.

An OBD reader such as Torque will tell you the engine temp the car is reading - its worth checking to be sure.

 

That's a relief. I wonder why it goes on and off. Backlight malfunction maybe?
I will check with OBD reader anyway.
Thanks
Jack

 

Jack, just an FYI. When the X100 reaches overheating temperature area, the air conditioning is automatically shut off by the ECU's programing.

Hope this helps you trouble shoot in the future.

John

 

I think it might be an optical illusion. The red part of the gauge is brighter than the blue at the bottom, so depending on your dimmer settings, the red can appear to be lit. Try this test, which is how my 2001 behaves:-

Turn the ignition on. The back light on the scale comes on and the red warning light, top right, goes on then goes off (this proves if the warning light is working).

With the headlights off. The back light is on at a fixed brightness

Turn your headlights on. You can adjust the back light with the dimmer on the steering column, from dark to bright.

Turn your dimmer all the way down, so the back light is very dim. Now turn your headlights off - the scale back light will light more brightly and you might think that red segment on the scale has come on.

Fiddle around with the dimmer, switching your headlights on then off and see if you can make the red segment on the scale look like it is going on and off.

 

Not sure the shape of the high temp warning light on a 2005 model, but on my 2002 it’s an oval shape, and located above the H portion of the gauge, at the 1 o’clock high spot

As others have pointed out, the rectangular shape red indicator is just there to show the high temperature area of the gauge and is only backlit with the rest of the gauge.

if it’s flashing on and off it might be as simple as a bad backlighting bulb.

 

The Temp warning light on the 2005 is oblong with rounded ends (race track shape}

Jack