[Nognar]

I had a look at the water pump and valves and its not the easiest thing to get to.

Hence took the flush/ thermometer/ VAGCOM route.

I need to drive the car for a few days to see what the temps are like inside the cabin. I just want a little heat in the winter.

The good news is the heater matrixes are flushed, clean and now producing some heat and clearly warm coolant is getting to them from the valves even if I am only reading 40 to 50c off the pipes. I am also getting 40c to 50c now on VAGCOM for the G150 and G151 sensors which is good news.

I agree if the coolant is 90c then you would expect that temp to be flowing but the other pipes in the engine bay holding coolant were all around 50c also. I suspect the cheap eBay thermometer and the thermal properties of the pipe wall itself to be taking the temperate reading down.

The main reason I was taking the temps was to check cold vs hot running on the car if coolant was being sent to the matrixes and that I had a drop in temperature from in to out of them showing the heat was being used.