so i had a false positive today that showed my temperature being high when it really wasn't...i added some oil, changed my parking lights, and did a general wipe down of the engine and after i did this the temp showed high, before i did this the temp was fine, after i did this and it was high...i must have hit a sensor or wire, so instead of my temp gauge being where it is always is, which is right around half way...it was up to almost the red space...see attached picture for where it was...no other warning showed up and there was no way the temp was any higher than before i added the oil and changed the parking lights...so i am wondering if any of you have any guesses on what i did and why the temp stayed up that high like reflected in the pic...my solution was to disconnect the battery and let it sit a few minutes, after reconnecting the battery the temp gauge showed normal and where it always is...also makes me worry that the temp guage is worthless, and now i am thinking of putting in a mechnical gauge somewhere...with 125,000 miles knowing if i am running hot is surely something i want to know...so what do you guys think caused the false positive?

 

"general wipedown of the engine" sounds like it could have angered the significant amount of wiring that is all over this engine. you may have had some water on something and once it dried out it stopped causing a problem.


and in response to that picture, it's a scary sight indeed. I took this picture once in my XJR, turned out that I had a broken coolant hose.

 

Well, if you install a mechanical guage and break the capillary whilst poking around in the engine, the temperature will read low. Redumdant syetems, properly installed are always "better", but where do you stop?

 

I have had a similar problem. Unfortunately, I don't know what caused it. My temp gauge would not "park". It would start from the middle and go way up to the top, but I knew the real temperature was fine. After a few drives it settled back down and goes to "normal" which is just slightly below the middle mark. I've checked all the grounds that I can find. It hasn't happened for a couple of months, but it is an irritant.

 

hey jaguarxjr02 when your temp gauge hit the high mark and the red light came on...did any other warning messages show up? just wondering and trying to see if when the car goes high temp if there are other warnings that pop up?

 

thanks jimmyL nice to know it has happened to someone else...so far since i disconnected and reconected the battery all has been fine...