The flickering or intermittent oil pressure warning can occur for basically two reasons. The less severe situation is that the oil sending unit has become obstructed by sludge or contamination so that the sensor is not getting a consistent reading of oil pressure. The oil sending unit is located just above the oil filter mounting assembly. It is possible that you are getting adequate oil pressure and flow, it is just that the sensor can not read this properly. This is something that a good Auto-Rx cleansing and rinse can correct, as long as the sensor is not bad. After all it is an electrical part. The second scenario would be that the oil pick up screen located near the bottom of the oil pan is clogged with sludge or what some folks call turbo turds. What can happen on these motors is that the bearings in the turbo charger roll up little balls of contaminants which get circulated back to the oil sump or pan. Unfortunately these little balls are the perfect size to lodge in the oil pick up screen. If they were smaller in diameter they would be able to make to the filter and be captured. Or if they were larger they would not get sucked into the mesh screen and sit in the bottom of the oil pan. But the reality is they are the perfect size. Just like a tennis ball getting stuck in a cyclone fence.
In severe cases of the oil pick up screen and tube being plugged up the only remedy is to have the oil pan dropped and the screen cleaned or replaced. On the positive side, if there is enough flow through the pick up screen, to safely operate the motor then running a Fast Track application of Auto-Rx has solved the issue for many 1.8t motor owners. As long as there is enough flow of motor oil up through the pick up screen to allow the oil pump to circulate an adequate flow of oil, Auto-Rx will clean the screen, the pick-up tube, and the oil sending unit sensor. Obviously Auto-Rx will also dissolve sludge or contamination deposits throughout the oiling system, including the turbo bearings, valve train, and piston rings. But this is only possible if there is enough oil flow to safely operate the motor.
