An external fuel leak wouldn't cause any of this, so you wouldn't be looking for or finding raw fuel anywhere. The raw fuel was going INTO the cylinders from bad injectors. And I think you have the cause vs effect swapped here. The dumping fuel from the bad injector(s) into the cylinders would cause the misfire, and then the unburnt fuel would cause the cats to glow. The misfire wasn't caused by the glowing cats, and the misfire didn't cause the fuel dumping in the cylinder. The dumping fuel was causing both.

The carbon on those pistons is the smoking gun(so-to-speak)

 

Oil diluted with fuel would provide bad lubrication, and poor oil pressure. He had a single scored bearing and poor pressure

 

Yeah, the big mystery on this one is zero oil pressure. No smoking gun on why it has zero oil pressure, and that is the only fatal issue. Misfires are fixable with proper troubleshooting, but zero oil pressure is not. If it was mine I would put it back together, prime the oil pump, and turn it over by hand until I had oil flow or with the starter motor until I had oil pressure (believe it or not both are possible).

 

He said the oil looked fine, thick and dark when he drained it. No smell of fuel, too. Oil dilution would not cause total oil pressure loss in my opinion...low, yes...totally, no. That mild scoring on those bearings would not cause total oil pressure failure either, in my opinion. Heck, the bearings in my wife's 03 looked like gravel ran through them for a month or two...and it still had oil pressure.

Anyhow, at the rate we're going...we may never know. To me, it seems as though there was a blockage of some sort or the key way on the crank wasn't installed, properly or at all, and it finally failed. Kind of wondered about the pressure relief valve in the oil pump...but, lve never seen the pressure relief valve cause no oil pressure, to much pressure...yes...low or none...no (not saying it couldn't happen, just never seen it in forty two years of being a mechanic and rebuilding several engines). Rebuild a 392 international engine one time, it would run for a minute or two...and die. Twenty minutes later...start right up and die again. Immediately after it died...it would crank over like it had no compression. So, l pulled a few plugs immediately afterwards the next time...low and behold...no compression in any of the cylinders. Wait twenty minutes, prefect compression. Believe me, you start scratching your noggin on an issue like this...one minute compression...the next minute you have none...lol. Ended up being the oil pump, it was creating so much oil pressure, it pumped up the lifters to the point they were holding the valves open. Changed the oil pump (which was factory rebuild, installed during rebuild of engine)...all fixed.

Brian.

 

Agree, unless l'm missing something...l've not seen a smoking gun yet. Carbon on a couple cylinders or oil dilutions is not a no oil pressure cause/affect, in my opinion.

Anyhow, good conversation for everyone to chew on.

(And l hope no one takes any of my disagreements personally...not meant to be a debate or agruement. We do the same thing at work, between the four mechanics, bounce different ideas/thoughts/past experiences off one another...not trying to prove anyone wrong or win the day by figuring out the issue first...just discusing the ideas thoroughly and trying to come up with a logical answer...that's all)

Brian.

 

I can attest to that. When I had a bad injector and my oil was full of gas, I still had pressure. It didn't go long that way but I did still have pressure even when the oil looked like dirty water.

 

Fuel squirting past an o ring has caused me misfires before, but that flaking carbon is definitely a poor compression burn of fuel in the cylinder or non atomized fuel in the cylinder just making its own little dumpster fire on the face of the piston, then getting blown into the cats.

But a lack of compression to the cylinder will do the same even with a good injector and plug/wires. I've seen that. We have all had bad MAFs with multiple misfires but I never saw flaking like that afterward.

I suggested an obstruction of passages above. When I had sloppy RTV blockage of my pickup tube, I blew air in the oil passages at the pump, pump bypasses, and again just past the filter. I never found anything but I didn't have zero pressure, either.

The one bearing thing also confuses me. If the bearing spun it could cover up the passage for that bearing only. I recall matching up the bearings to the oil hole but can they be installed backwards or upside down with the top on bottom and vice versa? I can't reember. It has been awhile since I had to mess with my engine.

That's the best I've got. But the little exdents (my word... The ears that hold the bearings in place) on the larger crank bearings would seem to make spinning them or putting them in wrong pretty difficult. What bearing was it? Rod or main? I don't know but either way it would be hard to make them spin.

Spun, wrongly installed to cover the oil hole, or or the wrong bearing (undersized). Best I've got for one bearing damage.