Multiple questions about my 1.9tdi

[Crasher]

Which sensor have you replaced, the one in the radiator bottom hose fitting?

[Smrendal]

I’ve tried replacing both the one in the bottom hose fitting and the upper one which I think goes on the circulation pump. The one thats fitted near the firewall in the back of the motor if you know What I mean?

[Crasher]

The grey one in the black plastic water housing unit on the end of the cylinder head above the gearbox?

[Smrendal]

Exactly!

[Smrendal]

Was there a follow up question to this?

[Smrendal]

The VCDS also tells me that the auxillary heater is dead. Can this be a main cause?

[Crasher]

The VCDS also tells me that the auxillary heater is dead. Can this be a main cause?

You have the Pr 7E6 electric air additional heater and not the Pr 9M0 auxiliary/parking heater and these are VERY prone to failure , especially on very early production Golf 5’s like your which was made on the 23.10.2003. These units (part number 1K1 820 015 Q) are rather expensive at nearly £400 in the UK. This can’t be causing your problem though, when these get too hot they can catch fire, it was the subject of a recall on very early cars.