Hi,
I have a mk7 golf gti. The coolant temperature guage always used to stay rock solid on 90 degrees when the engine was warm and never deviate. Well in the last month it only reaches 90 degrees if the car is stopped, when you get air flow needle drops to about 70 degrees. On 3 instances while driving the temp guage needle dropped to zero and the fans came on. Oil temp was fine around 75 degrees.
So I have changed the 2 water temperature sensors and still same issue.
The coolant level is fine, so no leak. My thought is it could be thermostat stuck open, but this wouldn't be the cause of the temp guage needle dropping to zero intermittently.
Anyone else had this. Its an expensive hunch to just replace thermostat and water pump if that isn't the issue.
Thanks
