Coolant temp gauge problems on A4 (B6) TDI
I am hoping someone out there can give me some advise on a problem i am having with my 2003 1.9 TDI 130 A4.
The coolant temperature showing on the gauge was only going to just above 70 degrees when i was on the motorway. I replaced the thermostat and the coolant temp sensor but there is still a problem.
The coolant temp will now get to 90 degrees but it sems to take a while and if i stop for traffic lights or traffic the gauge starts to drop towards 70 degrees again.
Tonight i got the temp upto 90 degrees and then left the car idling for approx 5 minutes and the temperature dropped down to 70 degrees. If i turn the car off for about 10 minutes or so the temperature again has dropped to around 70.
Is it possible that the viscous fan could be causing this?
I have checked the fan after 15 minutes driving and it seemed to spin freely with only a slight resistance and when the engine is cold the resistance goes.