This has happened a couple of times recently since its been cold, my temp gauge in the car goes up to nearly halfway initally then after a few miles it just drps back to cold?!!! I have adequate amoutns of coolant and anti freeze etc and I get hot air coming through the blowers. what could this be ? broken sensor? I dont understand I spent £800 on it this month and I dont want to spend anymore!!
HELP :o
Thermostat going.
I think all Saabs have that function. I know it happened in my 9-5 and it was the stat of temperature sender unit - both being cheap AFAIK
As Jim says, odds are a stuck (open) thermostat. If you stop and restart the car the gauge will start reading again. If the temperature doesn't get up to and stay in normal range within a certain time, the fault monitoring in the ECU detects this and turns the gauge off, and the EML on and also the radiator fans on low.
There's an outside chance it may be the sensor. How to confirm diagnosis- take the car for a drive until it's warmed up. The gauge may not get up to normal temp or it may fail again. Stop the car, park it up, restart and run at a fast idle for a few minutes with the aircon off. If the gauge gets to horizontal, it's almost certainly the stat.
However given that both are cheap, I'd replace the stat and sensor. If the sensor is reading low, your fuel economy will be suffering.
I had the same symptom on the Meriva - that turned out to be the thermostat sticking. Cx'd it for a new one and its worked fine ever since
As so cheap I changed both just to make sure and lo and behold mpg rose like phoenix said