Don't quite understand what you mean by not running up the dipstick, as far as I understand you, that will be caused by a low oil level which of course will cause the light to come on.

Is this the VW diesel engine? Also, is the oil lamp on all the time, or just at low rpm? This "spitting at the dipstick" I don't understand. I have seen the TDI blow the dipstick out, followed by some of the oil, but this only happens at high power if a piston ring sticks, leading to excess crankcase pressure. Is the engine a new one, or a secondhand, unknown unit? Any warranty? There could be a problem with relief valves in the filter head, or if equipped, the cooler between the filter and filter head. Oil filters can also be faulty. There is a common drive to the exhauster and oil pump, from the auxilliary shaft, this can be a problem, and cause total loss of oil pressure. Probably ok if you only get oil pressure warnings at low revs. Need a bit more detail from you, to help really.

If the age is correct,it's a VW motor.

Forget the dipstick, when the engine is running, the sump level effectively drops as the pump pulls oil out and sends it round the system. Returning oil, in some engines, hits the dipstick and looks like a higher level. If the oil lamp comes on at high revs, I still suspect the filter or relief valve in the filter head.

Good luck Rich. Hope to hear good news soon! Changing the filter head is not a big job, hope it gives right result.

Partial success then Rich. I assume your oil lamp is out, but you have a warning message that needs resetting?