Land Rover Repair: 2002 Discovery II, oil pressure sending unit, main bearings

Question
I have a 02 Disco with 108000 miles on it. I recently ran into a problem where my oil light was coming on at idle once warmed up. I replaced the oil pressure sending unit. No help. I checked the oil pressure and when warm I was getting 4 at idle and 30 at 2500. I replaced the front cover (oil pump), it is still doing the same. I was told the main bearings go bad regularly in the Bosch motor so I ordered them. I have the caps off and wanted to know if I needed to lift the motor and remove the crank. I hope not but have no clue. Any help would be great. Thanks.

Vince

Answer
I hate to say this, but I think you're barking up the wrong tree.  With Mobil 1 5-40SUV oil, the idle pressure can be 2.5lbs and be perfectly fine.  Before you go any farther, swap the sender.

As to the main bearings . . . if the front cover is off you can loosen the crank and change all the shells.  However, doing so with ensure a rear main leak, so you'll need ot pull the transmission to change that seal too.

If you don't want that risk, I suppose you can change the shells in the lower caps, and you can change the rod bearings.