Temperature alert mystery.

[VVC-Geeza]

Nearing the end of an 80 mile journey today the temperature display/alarm which was supplied through the club started to sound and it was displaying -99.The cars temp gauge had also dropped to zero.I was on a bypass but luckily able to pull into a layby about a mile further on.I checked the coolant level and it was normal.A few minutes later I restarted the car and both the cars temp gauge and the temp diplay had returned to normal temp again.I ran it a further 4-5 miles,still all normal.I then idled the car on the drive and the temp steadily rose until the fan cut in at 105 dropping the temp back down to 90.I repeated this several times without further issue.


What on earth happened,should I be concerned?Was it just a glitch with the temp display/alarm which also affected the cars temp gauge? It certainly has never happened before.Car is a 1.8T.



Temp alarm can be seen at bottom of pic.

[stevestrat]

Sounds like a hiccup with the temp sensor or wiring. The aftermarket temp readout feeds off the temp sensor, if the temp gauge drops to zero it indicates a loss of signal from the sensor, would affect the readout as well. If the ECU loses the signal it kicks the fan in immediately, you might not have noticed as you were driving at the time.

[VVC-Geeza]

Originally Posted by stevestrat

Sounds like a hiccup with the temp sensor or wiring. The aftermarket temp readout feeds off the temp sensor, if the temp gauge drops to zero it indicates a loss of signal from the sensor, would affect the readout as well. If the ECU loses the signal it kicks the fan in immediately, you might not have noticed as you were driving at the time.

Thanks Steve,I didn't notice if the fan cut in such was the urgency of finding a place to pull over.What you say makes sense,the display showing -99 suggests it had lost the signal.

[VVC-Geeza]

I forgot to mention in the OP that I also have a Ezee coolant level sensor kit fitted,again supplied through the club.Of course in the cool light of day had there have been a loss of coolant that alarm and red light would have triggered too

It focuses the mind though when an alarm sounds that you haven't heard before and things are whizzing by at 70 + mph

[T-Cut]

I also bought one of these gauges about ten years ago through Vindaloo here on the forum. I was sent some instructions as a PDF which I've just found on my backups drive. This screenshot tells you about the alarms.




I remembered it cos I had exactly the same situation and it frightened the pants off me. The radiator fan was also roaring at full belt. The wiring connector on the head sensor had worked loose.
TC

[VVC-Geeza]

Originally Posted by T-Cut

I remembered it cos I had exactly the same situation and it frightened the pants off me. The radiator fan was also roaring at full belt. The wiring connector on the head sensor had worked loose.
TC

Thanks for that Terry, it startled me too,particularly as I was on a busy dual carriageway with nowhere in sight to pullover.I'll check the plug on the CTS.
As mentioned I also have a coolant level sensor fitted which would have flashed and sounded had it been due to loss of coolant, but such was the panic I completely overlooked that.

[VVC-Geeza]

Seems it's not so uncommon,see here.