Got the oil pan and front cover off today to address my occasional flickering oil pressure light at hot idle 9 psi, 2000 rpm 34 psi. Engine was rebuilt with previous owner 20k miles ago. Was hoping to find something broke or glaring problem. There is a circular scoring in the oil pump recess part of the cover and clearance is between 0.005 - 0.006" of oil pump gear and the oil pump cover plate. Is that enough to drop my pressure? The scoring is visible but in my opinion not deep but can feel it with my fingernail.

I'll look for a slipped cam bearing next but what else should I be on the look for? All is pretty clean except for 1/8" sludge in bottom of pan, a small partial piece of plastic retainer and a two very small slivers of aluminum. Almost like the torn out threads of a bolt hole. O-ring on pickup and screen look ok.

Attached pics but never did before so if they don't appear let me know.

 

That is definitely bad scoring, warrants replacing cover and pump, what worries me is what caused it. I would keep looking for the culprit and any more damage. It sucks that that happened to a rebuild. Good luck, hope it's not too bad..

 

Thanks. What are you basing your statement "definitely bad scoring" on, personal experience? If so, what was the impact on pressure? Looks like a cover is $500. I don't mind replacing if that's the problem. I see so many posts where people replace the oil pump and little to no increase in psi.

 

Looking from the bottom up, can see all the cam bearings are in place and lined up in the block

 

Possibly the pickup tube o-ring also.

 

New oil pump gears are a good start. The metal that you saw is quite likely to be a rod bearing or cam bearing.

What info do you have about the previous rebuild...such as if they ground the crankshaft, then it would be good know "by how much" because to fix an oil pressure problem after a machine shop's grind job you go to oversized rod bearings of the amount of crankshaft ground.

Discovery 2s have 3 sizes of rod bearings:
Normal (use if there has been no machine shop work)
.01 oversize and
.02 oversize

Rod bearings are super-easy to replace once you've got your oil pan off. Those rod caps are a breeze to unscrew and the old bearings come out easily (ditto for the new rod bearings going in).

If you have worn rod bearings or if a machine shop ground your crank during the rebuild, then new rod bearings will improve your oil pressure.

If your motor is chattering like a diesel then you can likewise replace your main bearings since you've got your oil pan off already. Same deal there. New main bearings will likewise improve your oil pressure because they will be thicker than your old, worn bearings so there is less room for oil flow with the new bearings on...and that raises oil pressure.

 

When I did mine at 110,000mi., there was no scoring at all. That's how I know yours is bad. I can't say how much that amount of scoring will affect your oil pressure, b/c mine is the only one I've ever done. Maybe someone who has done more of these repairs (or regular maintenance since it's a Rover) can chime-in on that. What I suspect is that it wouldn't affect the pressure as much as you've noted, which is why I think that you might have another issue(s). Unfortunately, you may have to tear the whole engine down before you find it.

On the other hand, there could have been some swarf or residual foreign material left in the engine from the rebuild, or in the oil passageways that was lodged and came loose, and made its way to the pump and nowhere else; meaning you may have gotten lucky and the cover and pump are all you need to replace. Sorry I can't help more, you may just have to take a chance one way or the other based on your gut, your time and your wallet. -just my .02cents

 

As stated above oil pump gear & cover is not in best shape,, but how did it end up that way,, did mechanic use a brand new pump & cover at time of rebuild? If he did then his work sucks, because previous owner said the oil light would come on every now & then after rebuild, those gouges are created by something hard, hard enough to score the cast iron oil pump gears & softer aluminum cover,,, not all mechanics have same skill's nor all machine shops, it goes for rebuilds too,,
Not to discourage you but to give heads up of what to expect to find out next (& I hope I am wrong),
You definitely need to inspect crank bearings now that you have pan off, first to find out what stage of grind you have, (it will be stamped on bearings), (it really takes a grate machinist to make perfect first grind & even better one to get the 2nd grind perfect, & anything short of perfect on a crank grind is worthless), it will also tell you if crank was ground/polished correctly, inspect the one b4 the last main bearing first, Besides the scoring, if you see bobit is gone & copper visible, is a sign of bad machine work, do same with Rod bearing ,
If they are in good shape then you can get away with changing oil pump gear & getting rid of scores on oil pump cover's inner piece (one toward engine) by having it just barely polished by a good machine shop,,, if you don't want to spend the $500,, (buying a new oil pump cover is the best way to go but depends on budget),
But If bearings are not good then everything changes, depending how much you want to spend & put into it,, cheapest way will be new bearings ,,, it might hold for a while,
Best way will be to tear it & start with all good & known parts,, much much more costly,,
As said above, depends how much you want to put in it, & how good of a shape is everything else in the truck, will it be worth it, your decision,
(Sometimes it's worth it, & other times is best to cut the losses & just barely fix it).

 

Agree with most of the previous post...you need to dig deeper or contact previous owner for rebuild clarification (what was actually replaced and machined). That oil pump is scrap, granted, your pictures aren't the best...wish they were more from an angle...but if you are "feeling" grooves...it's most likely toast. As previously mentioned, only hard parts coming apart or breaking down (cam lobe, piston skirt, etc, etc) would/will cause gouges in the pump assembly. Dirty oil or normal bearing material loss (main, rod and cam) would/will not cause this type of condition.

Hopefully, whatever caued this wear happen prior to the last rebuild and they just overlooked the pump...or thought it "looked" okay enough to sell sometime soon. Hard to say for sure, since we weren't there. However, without such information...there is only one thing to do....pull all bearing caps and inspect for damage. If they look good, I'd suspect the previous rebuilder failed to replace the pump, for whatever reason, and you may get away with just a new pump. Because, whatever damaged that oil pump would have surely damaged the bearings and crank. Bearings will be stamped over sized, if machine work has been done to the crank.

Hard parts to inspect would be...cam lobes, piston skirts (which you should be able to see from down below, while turning over engine by hand, BEFORE removing caps) and timing chain/gear assembly.

All of this infomation is based on 40 years of being a mechanic, since you asked for references earlier...lol. Granted, I've not had a cup of coffee yet...so some info could be missing.

Good luck, hopefully the rest of the engine is in good shape and you're just looking at a pump assembly.

Brian.

 

The truck is worth saving. I paid somewhat of a premium because of the rebuild, accessories I wanted and overall condition. Bought as a long term toy and project but hoped to avoid internal engine problems that plague these trucks....I got just what I didn't want haha. I talked to the rebuild shop when I bought the truck so will call again on Monday. Agree to dig further. What is the process to check the main and rod bearings? Can the bolts be reused and torqued to spec?

The 2 metal shavings were stuck in the pick up screen. Is the oil pickup tube the only source of oil input? If so what ever caused that damage to the pump would need to be introduced after the screen, right?