Engine temperature 103TDI slow warming up and fluctuating once warm!

[Ricka]

Our MkV GTI is showing similar symptoms, do we think that it will it be a major exercise like the diesel?

[rosslm]

Not sure about MkV GTI get your mechanic to check it out, thermostats obviously like any working part will fail at some point. My car is going fine now temperature steady on 90 deg once warm. Just get original equipment I guess. My brother has a MkV 103TDI 200000K still has the original thermostat so I guess it's a bit hit and miss as to time to failure.

[Chocomashi]

Hello rosslm. I think I have the exact same issue with my 103tdi golf. Started happening a couple of months ago just after the 60 000km service. I have had the mechanic change the thermostat but the problem still remains. I'm guessing you have had no problems since?

[LongValley]

My 103TDI DSG with 140K on the clock has just begun to display the symptoms.
Pity it did not happen at 120K when I had the DSG service, new timing belt and new water pump. Another 4+ hours work.