Thread: Low oil pressure problem, Discovery 2 V8 4.0 2003

Hello landy owners..

Can anyone help me? I have 2003 D2 V8 4.0 (130 000km), I was sand driving and oil light came on whilst idling, I continued driving to safer grounds and then came loud ticking noise. I replaced oil and filter,engine stopped ticking and light went off, so I drove home.
The next day I started engine but the light came on at idle again.I decided to pull down engine,removing timing cover to find a CRACKED outer oil pump gear..
I replaced with new the timing cover (includes oil gears,relief valve,pressure sender and seals) New timing gears and chain as they where badly worn,exhaust manifold and flange gaskets all with new genuine parts ,I also replaced oil pickup o'ring, sump gasket and installed a oil pressure gauge, all done by the rover overhaul manual specs and thoroughly cleaned all parts before reassembling.
After all that work, and adding a thicker oil (15-50w instead of recommended 5-40w) I started engine to find it was running much smoother and quieter BUT still has zero oil pressure at idle after engine warms up ???? The pressure rises when engine is revved but then rapidly falls back to zero when revs drop??

Any help with this problem would be much appreciated..

Does anyone have advice for me on what I should check and replace whilst I am replacing cam, cam shells, lifters and pushrods ??