Well this is F***ed

Ok well the title sums it up I am pretty sure this motor is F'ed it does run still even with no oil pressure (gee I wonder why?) and an overall lack of power. So this is a pic of the rear main bearing cap where the oil pump mounts and where the rear main seal goes. That oval shaped and very jagged hole is clearly not supposed to be there. How or when this happened I could not tell you ive just been putting off tearing into it for way to long and now I wish I would have never investigated it.

So I'm obviously aware that this is basically a lost cause...that being said does anyone have any suggestions to either plugging this hole good enough to withstand the pressure or, a way to get ahold of another used bearing cap and just roll the dice that it will work. Or what are the chances of getting a used bearing cap and changing out these main bearings without completely removing the crank itself...or should I just slap it back together and just ride it till she dies since it does run and drive still.

I cant seem to think of a good solution to this problem as the right way would be to replace the cap with a new one and have the crank re-machined with the block and cap but I don't see it worth it on a 94 5.2l 318 with almost 200k on it and the body is rusted to s**t. so its not getting a new motor or a rebuild on the current... its just not worth it.

So if anyone has any ideas please shoot them my way.

Oh and also since I don't know when or what caused this I'm worried that even if I try to somehow patch it, what in the hell caused this in the first place? there are no marks of impact in the area, no missing pieces, the shaft to the distributor is in place and looks completely fine and the old oil pump did seem to be working fine and pickup screen was also not restricted in any way. Also when I removed the pan my oil was a little dark but there was NO debris at all in the pan. So where did it go? there is no knocks ticks or rattles at all when this thing is running, and a deadly consistent idle of 500 rpm.

Had you verified the no oil pressure with a mechanical gauge?

Unfortunately no. the in dash gauge shows a normal range of 40 upon startup and then once the vehicle runs for about 3 or 4 mins the gauge drops to 0 and there it sits for the rest of the time you are driving. (Yes I know the dash gauge is not very accurate) the trans and oil pan were covered in oil. So I assumed that it had to do with either the combination of the seals leaking or pump or pressure sending unit so I got the parts to replace all of it and discovered this upon teardown.

Ok so after spending some time online searching youtube and google images for rear main bearing caps I came across these images from other 318's with what appears to be the hole in them. so is it supposed to be there? an oil return port or something I would assume? take a look at these pics, idk about you but they look pretty damn identical to me. If this is indeed the case I will gladly feel like an idiot, I just want this thing back together.

The first pic is of the underside of my cap, the second is a side by side with mine on the left and one from youtube on the right, and the third is an underside shot of one from google as well. in each case the other motors were shown to be put back together with no problems.

Thought it was supposed to be there just judging from the fact that there was nothing in your engine but I've never torn one of these apart. I would say you could probably bolt it back together and when you get it running, mechanical gauge check. That'll tell you if the bearings are indeed bad.

Or now that it's apart you could simony go all new now lol.

Highly possible your sender is just ******

Yep

Yeah after confirming with a few of the guys at the shop it is I deed a return drain for oil to go back into the pan.

However since the rear main is leaking bad I will replace that. I already have a new oil pump and pickup screen so I'm just gonna put it in while it's apart the original does have almost 200k on it. And I also have a pressure sending unit I will be replacing to be sure. And yes I will be getting a mechanical pressure tester later today to test at least once it's back together (I did not have access to one before)

Thank you for the input for sure I always like to hear from as many sources as possible when I have a question/concern

So tonight after work I'll put all the new parts in and see what happens.

As long as you are this far, check a few of the rod and main bearings for clearance. Use plastigage as it's easy. You my still have oil pressure issues with a new pump with those kind of miles. Bearings are cheap and my give you another 50,000 or more miles.

I wouldn't get all regrind happy with the crank unless you want to do a complete rebuild. Bearing clearance is a major oil pressure killer.

Well it's fixed!

Ok so I got her all back together and had amazing results. Parts replaced were rear main seal, Oil pump and pickup screen, Oil pan gasket, Oil change and filter, Oil pressure sending unit switch, spark plugs, and plug wires. I also attached a pic of the problem parts that caused my issue (I suspect the old oil pump was fine but it was cheap so I replaced it) and the amazing pressure I still get out of a 200k mile motor and that's just at idle it will rise to I'd say 50 or 55 when under load or accelerating. And no I don't have a mechanical pressure tester and auto parts stores don't offer that tool for rental, purchase only so I'm just gonna roll with the dash Guage results.

Had the same thing happen in mine it was the oil pressure sending unit pressure sensor. it is freaky to see that on your dash when your driving anywhere though!

Fixed is fixed. 200+k mi and no knocks? I'd take it.

Congrats man