Dave WM

oh got it, I did not read completely, yes use the 6's for the reading. Sounds like the 5's were prob put in by PO, to help combat fouling from all the other stuff.

5's are a bit hotter, the 6's are the recommended. For testing the 5's will be fine, you just want to see if they change color. Being hotter would tend to burn off deposits a bit faster, but for testing I would think you would be ok, esp for short term test. fyi, hotter means the insulator is longer, taking more time to dissipate heat to the metal. hotter insulator means less build up. Down side is too hot could lead to detonation (pinging).

think its a knock sensor

The best way to test how the mixture is would be to 1st make sure the ign timing is correct, then using a brand new set of plugs, install and take if for a short test run, normal driving, of about 10 miles, then pull the plugs and read them. they should be very nearly white, just a tiny tan if any. I set my timing at 10 degrees with a idle of about 800 rpm. I don't know if this will be good enough to let you know about how you will do for emissions, but if they are turning brown after a short run like that I would think its going to fail.

did you use OE bearings or aftermarket? Maybe the OE's are designed to allow for custom clearancing?

If It was mine, I would remove the bearing caps and see how it spins. if it seems tight, I would then remove the center thrust bearing from the block and see how it spins (again without the bearing caps installed). I would think inertia should allow it to continue spinning if you give it a good start. If all seems well then install bearing caps and compare. But again this is just me talking, still hoping someone with exp will chime in and help you out.

hopefully someone with exp will chime in. I would think the center thrust bearing maybe an issue. I don't know if you are "suppose" to size them, Did the book say anything about what to do IF the clearance is too tight?

just a guess but that ZERO clearance on the thrust bearing sounds wrong. Perhaps a few light passes on a flat plate on the bearing sides to take it down a bit. This coming from a guy that had NEVER done it, so just my thoughts based on reading. I suppose you could try removing the thrust bearing and see how it spins as a test. Did you check with plastigage? what kind of assy lube did you use?

if it continues to leak after replacing the pan gasket, look for oil from the valve cover working its way down, if dry upstairs, look at the weep hole between the trans and the metal shield. If you see oil coming out of there, its prob a rear main and/or side seals. Only way to know for sure is to pull the trans/clutch/flywheel. then you can see exactly which if not both. Rear main you can do then then, the side seals will require pulling the pan and rear bearing cap.

found this post on hybridz, so guess a K11 no marking is still a good high volume hitachi https://forums.hybridz.org/topic/98987-l6-oil-pump-differences/?do=findComment&comment=1179425

here it is https://www.classiczcars.com/forums/topic/59887-horn-button-refurbish/?do=findComment&comment=547581

You all know I am going to try it out right? If for no other reason than pulling my old pump out to check it over.

Got the new pump, came in a box Nissan part number and label on the box from an ebay vendor as an Nissan OE part. However, no made in japan or hitachi markings the case. Only a K9 and a A22 stamped on it. I wanted to take it apart and look over the rotor etc... but it is not coming apart (removed the 2 10mm screws) easy so I backed off. I did put some fresh oil in it just to see it move oil around. So now I don't know if I have a cheap china knock off part of if this is what the current Nissan pumps look like.

OK ignore me when I complain... I had a NEW sender that I had yet to try (I used the one from spare engine which was new a year ago, but not the same brand as the old one (BA) that was in there. I put in the NEW BA sender and I am back to getting the same kind of pressure INDICATED on the gauge. Regardless of all the stuff I posted above. So the new plan is going to be to install the T connector since it is on the way, and confirm my readings. I have a NEW pump coming today, I may install just for the sake of science... but will def wait until I get that T in there and get a REAL reading of the oil pressure. My guess is I have NO problem... Sorry for the red herring.

I put a manual gauge on it, maxed out at about 50-55, on my spare engine I was getting closer to 65 with the same mech gauge I am getting the same results with two different senders. The mech reading seems to relate to the gauge (gauge and mech read the same approx. psi). I just expected closer to 65 on cold oil. I also checked the resistance readings using the same sender on both engines, the spare engine was consistently lower resistance (higher pressure). Of course never having taken a reading with the mech gauge before noting the problem means I am just assuming the pressure is actually lower than it was a week ago. (ignoring the electrical gauge).

NP you would not be CO if you did not ask! any other ideas on the cause of a sudden drop? I am thinking about pulling the pan to investigate further, and maybe remove the crank journals one at a time to look at the bearings while its off. I am assuming the biggest cause of oil pressure drop is thru the crank bearings... IF something bad happened there.

there is a aftermarket one that is a better design, much tougher, but does not have the softness as the OE.

I made a ring from some thin sheet copper, it was about 1/4 wide and about 1/32 think sheet. Solder the ends. the ring thin slips down just around the plastic part, digging into the foam a bit, but since its so thin (1/32) it slips in pretty easy. Just have to size the ring correctly before soldering so it grips the plastic from the outside tightly.

Well for now its on the drain plug. I have the new pump coming wed, and I picked up a Nissan OE gasket, pretty cheap only 50c.I like to use OE gaskets when I can get them. I can get some more rare earth type magnets at the local surplus store (sky junk) soon when I get the courage to drive up I4 in central Florida... they have a good selection of magnets and always interesting junk to look at.

I wonder if its possible some of he timing chain fragments could have got sucked up into the pump and scored it. I presume the filter would have protected the engine but not the pump as I assume the filter after the pump.

inside or outside?

tiny tiny bit of metal in the pleats of the filter, not a lot, just a few here and there. This is on a filter that I replaced after the timing chain guide came loose. there was some material worn from the chain were it rubbed against the guide.

above is a test you can do.

thanks ZH already on it, will report back (video) as soon as everything arrives. Would like to do a pre and post new pump video as well with a proper mech gauge just to see if there is any difference. I am going to check the oil for any metal sparkles as well. I dont know if its possible to have a bad bearing that would cause a loss of oil pressure with no other symptoms (other than metal in the oil). The main thing is just how it happened seemingly in one day. That is the puzzler. I also did a quick test with an ill fitting gauge, my test engine got to over 60psi no problem, but the engine in the car was more like 50-55 max. this makes me feel its a real drop, but will confirm and report back.