With regard to the 1.6 TDI CAYC engine, does anyone know if there is a tapping point into the main oil gallery, other than the pressure switch at the rear of the cylinder head, to connect an oil pressure gauge?

I doubt it.

Did you try measuring pressures at operating temp?

Yes and as expected its lower. I don't think there is a problem because if the oil pressure was that low in the main gallery the hydraulic lifters would be clattering. As expected pressure at the top of the engine will be lower but it would be nice to have an accurate way of checking. I wonder how VAG would check oil pressure?

7 minutes ago, fenny9 said:

I wonder how VAG would check oil pressure?

Via a tester plugged into the spot where the pressure switch is, according to the criteria I listed in your other thread. Unfortunately there's no guidance in the workshop manual about what should happen in between the minimum and maximum criteria, except by inference that it should rise towards 5 bar with rising revs, but no clue about what is 'normal behaviour'.

OK thanks for your help. I will speak to VAG and see what they say.

I have spoken to a VAG specialist who has confirmed there is no other pressure test point other than the switch on the back of the head and a gauge connected here should show a continual rising oil pressure as engine rpm is increased all the way up to max revs. Apparently this engine has a small internal toothed belt that drives the oil pump and although its not very common it can shed rubber particles and block the oil pump pick up filter.