Upper Little Red Light in Temp Gauge - RESOLVED
 

I noticed today that although the temp gage read normal (in the center of the gage)--as it's designed to be so the owner thinks the temp. is normal, the little red light at the top of the gage was on.

I was just short of pulling into my drive, so after I stopped and let the engine cool, I checked the coolant level, and it was as it should be. So don't think the engine was over heating.

Anyone experience this situation before? What's the consensus of the cause?


Cheers.

Strongly urge you install RealGauge.

Hello Chuck,
If you are referencing a little red light that is addition to the rectangular illuminated temperature "Red Zone", I would be for questioning if you have a hidden K40 radar detector that has been installed. (they are aftermarket, but appear to be factory). A telltale sign would be finding a second similar light and/or a hidden switch. (probably to the left, mounted in the Tach dialface would be the other light).
If you do indeed find a telltale sign, I may be able to shed some additional thoughts as I have a K40 on mine.

No telling what caused the red light. Electrical glitch, stuck thermostat, dodgy water pump, loose fan belt, etc. If your coolant level had been low then you should have gotten a "LOW COOLANT WARNING".

If it happens again, you really need an OBDll reader (ELM 327, etc) to read the actual coolant temperature. Or, you can install the "Real Gauge" from our member Jagwrangler. Either way, you will get a true temperature reading.

My coolant temp is normally 95-96 degrees celsius.


:icon_toast:

Stu

Now this is going to sound truly naff, but let me check a point. You are referring to the oval light which is above and outside the scale, and not to the red rectangle on the end of the scale? That red rectagle is unlit, though sometimes seems so, since it it appears to glow slighly from the dasboard lights. That caught me, once.

There seems to be some debate over exactly which red light this is .......

Attachment 201775
(click on the image to enlarge it)

...... item 5 - the red high coolant temperature warning light?

If so, it's reasonable to assume either:

1. the temperature was actually above normal
OR
2. faulty ECT sensor/out-of-range signal to ECM

Always essential to keep a close watch for any sign of overheating on the Jaguar V8. This would encourage me to monitor actual temperature and, as has already been said, the only way to do this is with Realgauge, ELM or Torque app.

Graham

My interpretation was that by"top of the gage" to be ~12 o'clock in contrast to the~1 o'clock hi temp obround.
Regardless, along with the others,I share in agreement to RealGauge and ELM/Torque.

Thanks guys..
Now I really am unsure, On the way out to get the paper this AM, I got inside the car and turned on the ignition and saw the #5 light as mentioned above, and also the RED rectangle scale. It was hard to tell which one was "lite" while driving yesterday. You can say with certainty that I am confused (not uncommon for me), so will have to drive around and see which one came on--or looked like it did. Either way, the suggestion for a RealGauge will have to be looked at again. A web site would be appreciated.

I'll post again once I find out what red light it was........

Cheers

Certainly you can disregard the red rectangle. This glows from referred lighting within the dashboard and, since the dashboard lights are always on with the ignition, it may appear illuminated even if your car lights are off. There is no bulb behind that red rectangle. The lamp referred to as no. 5 is another matter -is it on when you drive? I also have a possible overheat question, and have started a thread on this!

I had the realgauge for both water and oil in my XK8, but now I rely on the ultragauge which also has an alarm function.

How's that ultragauge working out for you? Does it actually pick up all the Jag trouble codes?

The ultragauge only gets P codes. I use it to monitor temp and fuel trims. It's a lot cheaper than a smartphone and with a little bracket that can slip into a crack between dash panels, easy to move from one car to another.

All,,
Well went out of town today in the XK8 and must confess that the "Little Red Light" I was concerned about was the rectangle light as mentioned by "Diddion" above, I had just never noticed it before, or the lighting was just right for it to look as if it had come on. The other red light never did come on. Of course this is after I ordered the "RealGauge". Oh well, once I install it, I'll know the temp all the time.

Thanks to all who tried to help an old fart trying to be young forever in my beautiful Jag.

Cheers..

Don't feel bad Chuck, I'm eternally 18 myself, and yeah, sometimes I can be just as dumb as one.

I've got a smart phone that I refuse to use for anything when I'm driving. Might as well put it to good use. But given that I'm blind as a bat without my reading glasses, trying to see the gauges and numbers on a phone screen would be impossible for me. I like analogue gauges whenever possible because at least I can figure out where the needle is. I'll probably opt for the unit version of the UltraGauge, I can stick it to the dash somewhere with velcro and out of sight to anybody else besides me. Besides, electrical work has never been my forte, so plugging it into the communication port is far easier for me than rigging up the RealGauge.

Chuck,

Better to be safe than sorry with anything that could have been a potential overheating situation by asking the question as you did.

I've added "RESOLVED" to your thread title. Always appreciated when the OP posts again with the outcome. Too often we never hear the conclusion of an issue.

Graham