Hello all,
Well, had the temperature gauge fluctuating sporadically between 0 and 90 degrees (the gauge didn't go over 90 though). This happens mostly when the engine is still cold -- first 5-10 minutes of driving -- then it stops at its normal position at 90C. Changed the ECT sesnor -- the problem remained the same. Now thinking of thermostat, but the logic says it shouldn't be thermostat: it doesn't go over 90C and mostly stays at 90C when the car is hot.
Does anybody have thoughts about what else can it be. It is weird that the gauge fluctuates only when the car is cold, so doesn't seem to be a bad contact.
Would appreciate any advise! Thankx!

 

Its the thermostat, I had the exact same problem, the gauge would fluctuate and then when it would get to 90 it would stay there all the time. Changed the thermostat and it was all fixed, I think it was something like 30 bucks.

Hope this helps, good luck

BLKDA4

 

Thanks BLKDA4. I called the dealer, he told me thermostat costs 150+tax. It comes together with housing and this is why it's so expensive. Can you tell me where did you get yours for 30bucks? btw, it changes from model to model: my model is 2004
1.8T