I recently got a 2003 Discovery w/ 218k miles and on the drive home I noticed the oil pressure light would come on at idle and I would hear a slight tick from the motor. First I changed the oil w/ rotella 15-40 with no change. after some reading I decided I would pull the oil pan, it had a little sludge in the bottom, maybe 1/2 inch but did not look too bad and nothing was blocking the oil pickup screen. I decided to proceed and pull the front cover hoping and thinking I would find a broken oil pump or major wear, other than a serious front main seal leak everything looked pretty good as far as I could tell. Not sure where to go from here, pull a main bearing and inspect for wear ? could anything else in the front housing cause low oil pressure ? any suggestions on where to go next ?

 

My guess is you have a walked cam bearing. Get under the engine and get some photos of each side of the cam journals. Post up here.

 

Got some, but going to try to get some more with someone rotating the crank, I hope its not a walked bearing, but would be nice to know before I throw parts and a new front cover on it

 

Unfortunately it looks like you were right, from what I can see looks like a bearing walked. time to start reading and see where to go next. Any suggestions?

 

Yeah, you have a walked cam bearing. You can pull the cam with then engine in the truck, remove radiator and dismount ac condenser - fold up out of the way. Depending on condition of bearing you may be able to reuse it. If it will go back in to bore, measure clearance between block with feeler gauge. If you consider re-using it, measure i.d. of bearing and od of cam journal and check against rave tolerance. If not usable, buy new cam bearing set. Have machinist turn OD of the replacement bearing down to .005-.003" under bearing bore (measure with a caliper or inside mic). Use Loctite 603 to glue new bearing in to place. Follow manufacturers instructions regarding the Loctite. Let me know if you have any questions.