Change the rear diff oil, as it started to make some clutch chatter in sharp turns. The oil was 2 years / 45.000km old. Then I noticed one missing bolt on the rear driveshaft flange, transfer case side. And all the bolts were loose.
Then I took off the oil pan to see what's going on with the low oil pressure with a hot engine and I found this in the oil pump pick-up screen:
Then I removed the oil cooler to replace it, assuming the water section was packed with sediment just like the radiator was. And it was packed with mud and pieces of dried RTV.
Now I'm curious how the oil pressure behaves, as the oil cooler barely got any coolant flow.
I've been driving like that for the past 55.000 km since I've owned the car and who knows for how long actually. The debris in the oil pump are probably from a cylinder head cover broken during injector removal.
I still have to change the front diff oil, build another front airdam and I'm ready for the trip to France...1900 km one-way.