1G Oil Pump the cause of my low oil pressure?

[ODDUWON]

Hey Guys, Do you think my "rebuilt" oil pump is the cause of the low oil pressure I am seeing on the stock gauge and in early bearing wear?
I saw some glitter in the last oil change. 1,000 miles on the oil and was 3rd change since break-in round 2 was completed, which has about 2,500 miles and 2 smog checks total. Glitter can be picked up with a magnet. Engine is stock with a .020 bore rebuild. Plastigauge when installing main bearings showed .0015 clear on all mains. Using 10w30 conventional from O'Reilly. Southern California Sunday Driver.

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I have been seeing oil pressure on stock gauge staying at the first line with 3k+ RPM. Will drop to basically zero if idle for more than a minute. Engine is quiet with no ticks or taps. New OEM OP Sending Unit from JNZ, no change.

I checked oil pressure with a new Harborfreight gauge, that i don't really trust, at the oil pressure sending unit hole (90 OFH). Cold start saw 85 psi. Up to temp and fans on saw 20 psi at idle, 80 psi #3k, 90 psi @4k, 120 psi @5k in driveway. Stock gauge still read very low.
Main and Rod Bearing picture is from last week with 2,500 miles on it (street/fwy Sunday driving). Oil pump that was in it was a ITM from 2005 think. The pump back cover has the ground off Hyundai logo and front says DOHC 2.0. I could fit the .008 feeler in at Tip clearance. Seemed to open up rapidly as I went away from the narrowest point. Some circular scuffing on the cover plate at drive gear. Easy finger nail catch+. I checked the 90 OFH ports a few weeks ago and all looked clear. Cleaned relief spring piston and bore with #0000 steel wool. Spring looked good, did not measure.

Back story:
When breaking it in the first time back in 2021 the stock gauge would read just above the first line, which is a bit less than where it used to before the rebuild. Then around mile 600 the pressure spiked to the end of high and pegged for 30 seconds as I got off the fwy and then fell back to just at or below the first line. Barely passed smog on rebuild 1. Shop set ring end gap to 2X limit in the Haynes manual and compression sucked. Blew out my dipstick. Used homemade boost tester and leakdown to determine rings not happy. Shop man said he replaced the oil pump gear also. Oil idiot light came on at idle a few times. Anyway, I re-honed using ball hone and ATF like I think 1990TSIAWDTALON linked a video of and put in new rings. I also changed all the bearings because they had the same wear I am seeing now. Drove it for 1,000 miles of break in and passes smog easy. Car runs smooth and doesn't burn oil now, but the oil pressure gauge is always lower than where I think it should be. Put another 1,500 miles on it just hoping the gauge is as inaccurate as I've seen other folks say on DSMtuners forums (pressure yes or no haha). Then I found the glitter.

Current state:
I bought a ACL oil pump and set of aluglide rod and half groove main bearings from Extremepsi after I saw the glitter. ACL pump cannot fit the .006 feeler and looks tighter all around compared to the other one.The ACL case machining/casting looks rough, which others have mentioned, but I have a concern about the balance shaft section of the case. Should it look this rough? It is machined below the case's deck surface, but it is not smooth. Not sure if the balance shaft touches this surface or not, but i am concerned it would eat up the shaft face if it did. I put the spacer, sprocket, and bolt into the shaft with the ITM case and there is a little bit of play in and out. I slid a feeler gauge under a flat bar there on the bench and it is about double what the ITM was. Can't remember what feeler I used, i think it was .009 on the ITM?.

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Also what is up with this ACL casting machine work? Should I clean this up with a burr, or just leave it? This is the main oil passage I believe.

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Any suggestions on other places to look for pressure problems, or other sources of the glitter that attracts to a magnet would be greatly appreciated. Also opinions on which brand oil pump/front case to buy in 2025 would be cool.
Thanks.

 

[ODDUWON]

I took a look at the bearing wear locations this weekend. Seems mostly the front main has wear and all of the rod bearings do too.
I see there are (2) holes feeding that bearing from the front case. 1 direct off the main oil gallery on the exhaust side of the engine like the other main bearings, and I think the 2nd is off what looks like a back pressure channel in the case that feeds from the firewall side of the bearing.

When I put the OFH relief spring and piston back in I lined the hole in the piston up with the hole toward the block. I can still see the hole and put a pick in there and can carefully move the piston with moderate pressure prying off the housing. Could this spring just be weak, it is original w/ 198k on it? I have a MD050299 from JNZ but am not sure if this is for 1990 DSM, EVO3?, or for use in the water cooled OFH. I asked the AI (Grok) and it's no help and I don't trust it with part numbers this rare. The more questions you ask it back to back the more blah blah it gives you.
Does anyone know which spring part number is correct for the 1990 air cooled setup?

Regarding the front case from ACL: I purchased a Topline case and the casting is EXACTLY the same as the ACL case. Same sloppy channels. Same harsh machining that looks like they missed the hole as pictured above. Same bolt style and color. The inside of the gear cover has the same 53(?) stamp too. Only difference is the Topline has "made in Taiwan" laser etched near the balance shaft tensioner hole. Otherwise they are identical. The photo on Rockauto showed it having the hyundai kia logos on the case, but that is not what showed up.

What else could be giving me low oil pressure on a stock setup? (OFH is unmotified, I DID modify the Cylinderhead witht the oil port mod - very square like, I took the flat bottom down evenly by what I thought had been removed when head was surfaced.)
Could my oil cooler be pluged up some causing a restriction? Pressure gauge reads after the oil cooler in Jafro's flow chart.
Could the thermostatic valve be stuck halfway open? (rewatching Jafromobile - 4g63 oil filtter housing video now)
Could an oil jet be stuck open? The cylinder walls and pistons show no shiny spots and are very oiled up.
Oil hole on the balance shaft bearings are lined up.
I took a cam out and all the bearing surfaces and cams look smooth and uniform.
reading through this thread. maybe I could shim the relief spring to increase preload? https://www.dsmtuners.com/threads/low-oil-pressure-at-idle.544651/
Jafro said the balance shaft dosent touch anything in the case except for the oil seal, but he and likley most here don't run the shafts. I have them because stock.
Rewatching Jafro's video 6&7-Bolt 4g63 Front Case & Oil Pump Rebuild. I think I measured my drive gear clearance incorrectly. Will check again tomorrow.

running out of ideas on what to check.

What is a "quality" aftermarket oil pressure gauge? The harborfreight one I have doesnt meeet this criteria I think. Jafro says to test at the head and the block to determine If you really have a pressure problem. My bearings seem to say yes, but more data is good.
What would you guys suggest here? what brand mechanical? what brand electronic?

 

[We're on Boost]

What is a "quality" aftermarket oil pressure gauge? The harborfreight one I have doesnt meeet this criteria I think. Jafro says to test at the head and the block to determine If you really have a pressure problem. My bearings seem to say yes, but more data is good.
What would you guys suggest here? what brand mechanical? what brand electronic?

For just doing some tests in the driveway, I'd keep it simple by using a mechanical gauge, like you tried to do with the Harbor Freight gauge, but with a better quality mechanical gauge.
So for that I would probably use a Marshall CW00100 which will only go to 100 psi, but if you are basically wanting to be sure your oil pressure isn't too low, that is enough! That will also be a perfect gauge for checking your fuel pressure at the regulator.
Here is the Marshall page that shows their gauges of this type (for oil and fuel):
Pressure Gauges
And here is the page for the CW00100, also called the CW 0-100 PSI:
CW 0-100 PSI
This is one of their easier gauges to buy, I bought mine on Amazon, here:
CW00100

For an electronic gauge, well ..., That's what you would want if you want a gauge in the car up on the dash reading all the time. My experience is with the AEM gauge kits which come 2 ways, one that only goes up to 100 psi and one that goes up to 150 psi. Both come with the brass sensor only. I don't see any option to get them with the stainless sensor instead (they are completely interchangeable though).
This can get complicated and expensive (the AEM electronic gauge).
You should read in my build thread, page 3, posts 52 and 53.
Then if you also read posts 54 and 55 you'll see what I have to say about oil pressure, which might only be valid for "race" style engine builds, I don't know.
BTW the idea of having the electronic sensor "remote mounted" like I did is not a wild assed over kill idea. It's pretty generally recommended, including by some people in here, and by AEM.

A potential problem with the AEM gauge idea is you might have trouble logging it because of our 1g ecu inputs. So then you'd have the gauge, but no logs of it. Our best input for reading voltages is the IAT input, which you are probably using either for the MAF or for an air temp sensor for speed density. If you are already using it, then people sometimes try to use the EGR input, and that isn't such a great input for reading voltages. I haven't tried it, I've only read about this, usually when it's about a wideband. So you might have only the gauge. Anyway on my car, I'm logging my oil pressure sensor with another box entirely, an ecu+, which has some good accurate inputs for logging small DC voltages.

Oh I almost forgot. I have a brand new 1990 oil filter housing sitting right here in the living room, all nice and clean, and it wouldn't mind posing for a couple pics. So you said something above about not sure where the relief piston should sit in the bore. The groove that goes around the piston is partly visible when you look into the relief hole. I could shoot a pic of that if you want.
I don't know what the part number is for just the spring.
But the 1990 OFH complete is MD132912. You might still be able to buy one from Amayama. That's where I bought mine in 2023.

 

[ODDUWON]

You should read in my build thread, page 3, posts 52 and 53.

Thank You for the Build thread recommendation. It's cool to see an example of a remote mount Oil Pressure Sensor. I have read a few times about it but not seen photos. Your body kit looks cool in the Boost Garage.

I don't know what the part number is for just the spring.
But the 1990 OFH complete is MD132912. You might still be able to buy one from Amayama

I had just ordered this a few hours before I read your post. Just showed up a few days ago. Was around $125 shipped from Japan Amayama Warehouse.

I would probably use a Marshall CW00100 which will only go to 100 psi, but if you are basically wanting to be sure your oil pressure isn't too low, that is enough!

I will order this gauge to test once I get everything back together.

After watching Jafro measure his oil pump again, I took another look at my original and the ACL replacement.
you can see some scoring on the original's pump cover and replacement gears.

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Originally, I measured by sliding the feeler gauge tip in perpendicularly near the bottom of the casting (3 o'clock in the gear photo) but I should have been measuring by sliding it in near the drop off where the red arrow is.
Old Pump housing with replacement gears: Could fit the .009 feeler in there. That is basically service limit of .0098. You can also see a defect in the casting there. I did not look at this before I had the machine shop rebuild the bottom end (they asked for the pump - they also replaced my crankshaft because the snout was bent, is what they told me - these Dudes are in Hot Rod Magazine for V8 builds locally, so I thought they would do a good job with this. They did work for Road Race Engeneering back in the day).
NEW ACL Pump: I could only fit the .005 feeler in there, which is tighter than the in-spec values of .0063 - .0083.
Funny thing is i put the New ACL gears in the old casting and got the same .009 feeler in there. I guess the casting is just bad, but it was making pressure fine before I took the engine apart many years ago. Not sure if some casting broke off when the shop cleaned it or what. I believe the housing is trash now.

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I was complaining about the ACL casting roughness, so I took the dremel and blended out the chunky area. Then I laid the gasket on to make sure I did not make anything too big, and wow that gasket blocks off much of the openings, so that chunky spot wouldn't even matter flow wise. Jafro explained, while spraying himself in the face with the water hose, that the oil pump does not provide pressure, it provides volume. The pressure relief valve is what makes pressure (finger over the garden hose).

Looking at the new 90 OFH I would say the piston may sit just a tiny bit farther into the housing than my NOV/1989 original. Also, the piston hole is not facing the opening in the new one. Not sure the spring was bad, but was a worthwhile application of the parts cannon to have a fresh OFH and thermostat for the oil cooler.

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I will flush the oil cooler before I put everything back together this/next weekend. Plan to put degreaser in there and gently shake it at all angles for several session of several min. and then flush with hot soapy water, then garden hose, blow out with low pressure air, let dry in the sun, put in oven with pilot light heat for a day or 5, and then flush with clean oil befor putting back in. If anyone could recommend a better way please let me know.

 

[pieceofcloth]

I don't have oil pressure issues but I removed my front plate which was aftermarket the other day. I had the same scuffs around where those pump gears go. It looked like my gears took a chunk out of the plate. I just purchased an oem front plate to resolve this and another issue I have.

I believe around 90% of the aftermarket front plates are bad castings. This is my 2nd aftermarket.


Remote mount the new oil pressure sensor. If you need help with that, I can show you which parts or how to assemble. I had got my pieces from Amazon.

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[We're on Boost]

Looking at the new 90 OFH I would say the piston may sit just a tiny bit farther into the housing than my NOV/1989 original. Also, the piston hole is not facing the opening in the new one. Not sure the spring was bad, but was a worthwhile application of the parts cannon to have a fresh OFH and thermostat for the oil cooler.

The piston position in your new OFH looks exactly like the one I bought new from Amayama in 2023. The piston hole is not facing the opening in mine either. I don't think it matters which way that hole is facing.

Yeah I think starting fresh with a whole new OFH is the best. New relief parts and new thermostat

When English Racing put my engine together in 2015, they bought a brand new 1990 OFH for it too. So that's what's on my car still now, I've never seen the inside of it. All I know about it really is that the relief valve starts opening at about 74 psi in the actual operating engine (not any bench test). Which is awesomely close to what it says in the 1990 Technical Information Manual on page 9-20. And I'm 99.9% sure that ER didn't change or modify it in any way.

I'm not going to say anything about the oil pump itself because I've never had to work on one. Except, wow that chunk that broke out of the old housing is pretty big - scary.

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[19Eclipse90]

I have a MD050299 from JNZ but am not sure if this is for 1990 DSM, EVO3?, or for use in the water cooled OFH.

Does anyone know which spring part number is correct for the 1990 air cooled setup

I don't know what the part number is for just the spring.

Sparingly following along, just wanted to pop in and mention the 1990 air cooled OFH uses the same MD050299 spring that every other 4G63 powered DSM originally came with in its oil filter housing.

 

[ODDUWON]

Remote mount the new oil pressure sensor. If you need help with that, I can show you which parts or how to assemble

Thank you for the photos. looks like a BSP nipple to a f to f adapter to quick connector (AN?) and a flex line to your remote plate? If you had an easy list of amazon parts I would try that. Is this set up just to relocate the oem sending unit, or would you use this to also hook up the 100 psi gauge We're on Boost recommended for driveway testing?

Here is the Marshall page that shows their gauges of this type (for oil and fuel):
Pressure Gauges
And here is the page for the CW00100, also called the CW 0-100 PSI:
CW 0-100 PSI

The piston position in your new OFH looks exactly like the one I bought new from Amayama in 2023. The piston hole is not facing the opening in mine either. I don't think it matters which way that hole is facing.

Thank you for the confirmation. I feel better about having a new OFH in there too. I saw that one of Jafro's pistons you could see the hole, but like you said the orientation may not matter.

just wanted to pop in and mention the 1990 air cooled OFH uses the same MD050299 spring that every other 4G63 powered DSM originally came with in its oil filter housing.

Thank you for this. I know Jafro measured several springs and had slight differences in length, but as far as getting new, it looks like there is only 1 part number available now.

What do you guys know about cleaning the 1G oil squirters? I think the machine shop "cleaned" them, but I did not check their work. I used the AI to find this thread where 1990TSIAWDTALON describes using a wire to clean the banjo check valve. https://www.dsmtuners.com/threads/oil-squirter-question.541909/#post-153867545
looks like I just wiggle the wire and flush with brake cleaner to clean everything out? Kinda like the carb jet on a lawn mower. 1990TSIAWDTALON said always use new crush washers here. I see "(8) oil pipe (USA)" aluminum, crush washers in my fel-pro cs 9086 kit so I will use those.
I don't have any evidence the squirters are stuck open, but since I'm in there it would be the last thing I could check and clean in the oil system, as far as I can tell.

Oil cooler cleaning was a success. I learned that I should have marked the position of the torqued banjo bolts in the cooler before I removed them. I torqued them on the bench and the bracket for the lines was not lining up right. Had to take it out again, loosen the banjos, put it back in, snug it and mark position, then take out again and torque on bench (29-33 ft/lbs) and reinstall. Boss is 1-1/16" wrench and banjo was 15/16", or at least that is what fit in my tool set. I took the center support bracket out - the one that fits around the hood latch - and loosened the power steering line bracket under the reservoir to give enough room to shift the cooler and lines toward the passenger side and slide it down between the core support and the plastic shroud that connects to the bumper. Lots of plastic clips down there wow.

 

[We're on Boost]

Is this set up just to relocate the oem sending unit, or would you use this to also hook up the 100 psi gauge We're on Boost recommended for driveway testing?

Well for driveway testing with a temporary gauge, you could put the gauge on a hose and use it hand-held. Like in this video, although this is a 2g. This guy's gauge is nice, big, easy to read, and probably way too expensive since it's a snap-on.
Even with the inexpensive Marshall gauge this will cost some money for the fittings and some hose.
I don't know what would happen if you just screwed the Marshall gauge directly into the OFH. It is liquid filled so it can take some vibration, but I'd be almost scared to do it that way.
If you dial the video back to about 13:02 you can catch the guy's choice remarks about the stock oil pressure gauge.

 

[ODDUWON]

Well for driveway testing with a temporary gauge, you could put the gauge on a hose and use it hand-held. Like in this video

I see in the video he has a hose installed into a port on the rear of the OFH. That is a 2G so I am not exactly sure, but I see a photo of a 2G sending unit facing the firewall in the same port from an internet search. The 1990 OFH the sending unit faces down. Idiot light switch faces forward. Thermostat and pressure relief spring face the firewall. I believe I am supposed to read Oil pressure from the sending unit hole

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I think this Glowshift adapter is the correct male and female type/size to connect the Marshall gauge and 1990 OFH. I would just put the adapter on the gauge and install it facing the ground and crawl under to read it? I think a brass ntp 90 may not offset the gauge far enough to clear the housing.

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I have this Maddox gauge from harbor freight. Says item #4 is 1/8" BSPT male to 1/8" npt female (made of soft chinesium). I used this and the hose with the gauge to measure the first time, but I don't have faith in the harbor freight gauge. I measured from the sending unit hole. Did not leak oil during test. Adapter looks tapered.

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Should I trust the hose in the Maddox kit, or just get the Marshal and the glowshit adapter and crawl under to read? Does anyone have a recommendation for a hose with fittings? or should I just do the adapter and gauge? I want to test at the head also per Jafro's recommendation in his video.

Remote mount the new oil pressure sensor. If you need help with that, I can show you which parts or how to assemble. I had got my pieces from Amazon.

Do you think the 90 elbow will fit the Marshal gauge and clear everything when installed like you have? I am keeping stock sending unit location an not worried about vibration (I have balance shafts). The set up in your picture is what I had in mind.

Would this work for measuring at the head also, or is that a different adapter/thread size there? I believe I would measure at a gallery plug in the head near the turbo oil feed line. Which one of these 5 gallery plugs is the correct place to measure pressure at the head? Anyone have a thread link? The AI is telling me dsmtuners read from the oil feed line from the OFH, but where do I get pressure coming out of the head? At the banjo hole? I have the stock oil hard line and banjo to my EVO III 16G turbo. Would I need something like this adapter for reading at the banjo "Fitting Adapter NPT 1/8" Female Pipe to Metric M12 M12X1.25 Male"? Thanks for your help Guys.

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[We're on Boost]

I believe I am supposed to read Oil pressure from the sending unit hole

Yes, use that one, the one you put a red arrow on. It is unfiltered oil there, (it's before the filter) which is what you want normally for a gauge because all the oil pressures you see people reporting are taken from before the filter. Also you don't have to worry so much about accidentally getting some dirt in there while you have it open, being as how it's unfiltered there anyway.
Here's a pic we've been using for a long time that labels the 1990 OFH ports:

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And that port is 1/8" British tapered pipe thread, so the male pipe thread you put in there should also be tapered, and it should be 1/8" British, not NPT.
Both of the 1/8" BSPT fittings you show (the Glow Shift and the Maddox) are ok for the British thread then.

If it was me, I would sure rather have some rubber hose between the OFH and the gauge, for reading in the driveway. I wouldn't put my head underneath it to read a downfacing gauge while the car is running. You could lay the gauge down on something if you had 2 or 3 feet of hose there, or maybe have the gauge run around to a position where you could see it while you are sitting in the driver seat running the gas pedal. Or you could take video of the gauge.

On that Maddox kit, I don't really get it what fittings they show on the bottom of the gauges. They look like quick disconnect air hose fittings, male. Did you use it like that? Or do they have some different fitting that you put on there to use with liquids?

Pre-assembled hoses are amazingly cheap for what they are, considering that fittings cost a lot when you start buying them one by one. But most of the small stuff (1/8" is small for oil) is going to be sold as brake line, which is ok I guess if it's teflon lined inside. Or if it's sold for oil, it would most likely be sold as a turbo oil hose. And most will have AN fittings on the end rather than pipe thread, which would require AN to pipe thread adapters.

If it was me, I'd buy one of these STM -4AN turbo oil feed lines, which are female -4AN on each end, so I'd also have to get a couple of -4AN to 1/8" NPT adapters for each end of it. I'd get the longest hose (28") which is $33 plus shipping. The -4AN to 1/8" NPT adapters for each end would probably cost 4 or 5 bucks each. It seems expensive I know. There should be a cheaper way to do it with a less fancy rubber hose but it's not jumping out at me at the moment . But this STM line has a 90 degree elbow on one end which will be good for coming out from under the OFH without running into the frame or anything else. Then with the AN fittings, the advantage you have with them is you can rotate the elbow wherever you want it aimed, and then tighten the AN fitting without changing the position of the elbow. You don't use any sealant on AN fittings which is also nice. Use sealant only on the pipe threads.

If you can do a hose-to-gauge setup with the Maddox parts that you already have, that could be another way to go, and a lot cheaper. If you can hook it up to your new gauge in a good way. Still puzzled by what looks like a quick disconnect there.

On the ports again, you can also use either one of the front-facing ports for a gauge. They are unfiltered oil. They are also British tapered pipe thread. 1/8" and 3/8". You can see in my build thread post #52 and #53 that I'm using the 3/8" port for the hose that goes to my oil pressure sensor.

 

[We're on Boost]

If you go the AN oil hose route and need the AN to NPT adapters at each end, STM also has those in male to male for a lower price even than Summit racing does:
Vibrant #10292 -4AN Male to 1/8" NPT Male *Steel*

STM doesn't have the AN Male to pipe Female adapter, so you would also need a 1/8" pipe coupler which is female, and you would use it on the gauge end to connect male pipe to male pipe. Like this one:
1/8" NPT Female × 1/8" NPT Female Coupler with Hex for wrench

 

[ODDUWON]

If it was me, I would sure rather have some rubber hose between the OFH and the gauge, for reading in the driveway. I wouldn't put my head underneath it to read a downfacing gauge while the car is running.

Yeah, crawling under to read the gauge would not have been the brightest idea. Thanks!

On that Maddox kit, I don't really get it what fittings they show on the bottom of the gauges. They look like quick disconnect air hose fittings, male. Did you use it like that? Or do they have some different fitting that you put on there to use with liquids?

The gauges in that kit had male air compressor hose style quick connectors. The hose had a female air line connector and the other side screws into the adapters. the direction suggest oil will enter the hose. I don't see any oil in the hose from when I used it, and don't remember any dripping out. Maybe I got a bad reading by not purging the air in the hose? Directions just say hook it up and read gauge after warming up.

If you go the AN oil hose route and need the AN to NPT adapters at each end, STM also has those in male to male for a lower price even than Summit racing does:

Thank you for the links. I will get those from our supporting vendor.

Happy Independence Day weekend everyone.
I took the oil squirters out and cleaned the first one with a single strand of wire and blew it and the banjo check valve out with brake cleaner several times.
When I took the 2nd one out and started cleaning I found a crack at the jet pipe base. the other 3 seem fine. Is this something that would contribute in any amount to low oil pressure?

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STM shows the 1G squirters (MD329806) are discontinued as of 2022. They have a note that says you MAY be able to use the EVO 8 squirter (MN143460), but you must research first. The original part shows up on Amayama, but the ship date is late July/early August, if they actually have them. You don't know with them until you order and they review it first.
How likely are the banjo check valves (MD050249) to go bad? I see ExtremePSI has them for $40 each. I see them at Amayama for slightly less, but same late shipping date, if they have them.
What would you guys do here? All new squirters AND banjo check valves? Post a "wanted ad" in the classifieds for a good used? 190k miles on original parts.

 

[We're on Boost]

The gauges in that kit had male air compressor hose style quick connectors. The hose had a female air line connector and the other side screws into the adapters. the direction suggest oil will enter the hose. I don't see any oil in the hose from when I used it, and don't remember any dripping out. Maybe I got a bad reading by not purging the air in the hose? Directions just say hook it up and read gauge after warming up.

Ok, hopefully those Maddox quick connectors are proper hydraulic hose type couplings. I don't know much about them, but I think they would have a check valve in them so that oil doesn't come out when you pull them apart. Oil should definitely go into the hose. The air that is in the hose might not be able to escape but that is ok, the air will compress and be at the same pressure as the oil that is pushing on it. This is all fine as long as it doesn't leak, and as long as the check valves actually open when you push the connectors together. But I think they are designed so that the check valves have no choice but to open when you push the connectors together.

If the quick connectors on the Maddox gauges have 1/8" NPT thread where they attach to the gauge, I would just take one of those off of the Maddox gauge and put it on your new gauge. Connect it all up like that and see what happens.

Also, here's an Amazon page that you could scroll down through to look at dozens of different hydraulic hose quick disconnect fittings. You should look at these and see if what you have in the Maddox kit is kind of the same idea.


I've never had to mess with the oil squirters so I'm not going to say anything about them, except that if you still have the stock cast pistons in the engine, then I think it's preferable to have properly working oil squirters in it. If you have forged aftermarket pistons, then it's probably better to delete the squirters, like my car, and like many others have done who have high powered cars with forged parts inside.

 

[DSMPT]

Do you think my "rebuilt" oil pump is the cause of the low oil pressure

What do you mean by rebuilt?
It's possible that the pump causes low pressure but it's rare, and in that case, you may have seen massive damage under the pump gear cover.
Besides the internal leaks such as the pressure relief valve stuck open, fallen oil jet check valve etc, one common cause that oil pump not to build oil pressure is the oil pickup tube/strainer related, like smashed oil pan and sucking air due to cracked tube.

Then around mile 600 the pressure spiked to the end of high and pegged for 30 seconds as I got off the fwy and then fell back to just at or below the first line.

When the circuit has a short (grounded), the oil pressure gauge would read the max. Like if a ripped wire is touching the chassis accidentally or so.

Oil idiot light came on at idle a few times

This too. If the wire for the pressure switch is grounded for some reason, the oil pressure warning light comes on.

Shop man said he replaced the oil pump gear also.

Why did he replaced only the oil pump gears? If the gears were damaged, the front case should have been replaced too.

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I am seeing on the stock gauge and in early bearing wear?

IMO maybe you're just overthinking.
It's hard to tell by only this pic but if it's only the surface color changed, like getting dark-ish/shiny-ish. Usually that's kinda normal wear and that's a part of break-in. Break-in is not exactly only for the piston rings to seat. The color changed means that bearing was getting fitted in with that specific journal.
But I personally don't recommend to open the rod caps to check the bearing unless it's really necessary. Because once you remove the rod cap, the bearing's crush height won't be the same after it got some heat cycles. Less crush height means less tension to hold the bearings. Also there is a chance that some thing like dirt or oil whatever get into behind the bearings. This would cause a different clearance from when you built.

In case if that's a damage by low oil pressure, you should have seen damages on rod bearings more than on main bearings.

Glitter can be picked up with a magnet.

Could be from cylinder wall/piston rings. Not from bearings.

Should it look this rough?

Aftermarket front cases are more or less like that.

Not sure if the balance shaft touches this surface or not,

The balance shaft is floating, so as long as it's installed properly and there is oil pressure, it won't touch.

I put the spacer, sprocket, and bolt into the shaft with the ITM case and there is a little bit of play in and out.

That's normal, it should have the in/out play like the video below.

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Also, the piston hole is not facing the opening in the new one.

That's not important that the hole is not facing the opening. That's why there is a groove. The hole is to purge/drain air and oil to prevent to build up pressure behind the plunger. As long as the groove is connected to crank case, it should work as it should regardless of the hole position.

Could my oil cooler be pluged up some causing a restriction?

It could. If the oil cooler is clogged or just block off the oil cooler ports, you may see less oil flow to main oil gallery when the oil gets hot.

Could the thermostatic valve be stuck halfway open?

It could. But it's rare and anyways even this bypass valve gets stuck open, it won't cause low oil pressure since it's just a oil cooler bypass valve. When the oil temp is not hot enough, it's always open.

Could an oil jet be stuck open? The cylinder walls and pistons show no shiny spots and are very oiled up.

It could. If oil jet one way check valves get stuck open, it would affect low side oil pressure, not high side. It's rare though.
And oil jet wouldn't affect the cylinder wall lubrication much since the main purpose is for cooling pistons, it jets oil to underneath the piston crown. Cylinder wall is lubricated mainly by crankshaft splash and oil from rod bearings, and also the rod oil jets to the major thrust side cylinder wall from the stock rod oil jets, if you have the stock rods.

Would this work for measuring at the head also, or is that a different adapter/thread size there?

It's 1/8 BSPT, the same as the OFH port.

I have the stock oil hard line and banjo to my EVO III 16G turbo. Would I need something like this adapter for reading at the banjo "Fitting Adapter NPT 1/8" Female Pipe to Metric M12 M12X1.25 Male"?

I was using the M10 factory oil feed port with a AN/Banjo fitting to check the oil pressure for the turbo for a while. The M10 factory turbo oil feed and #1(1/8 BSPT) in your pic have the same pressure. That location is the feed/inlet for cylinder head at pre HLA regulator and that comes direct from the block main oil gallery.

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When I took the 2nd one out and started cleaning I found a crack at the jet pipe base. the other 3 seem fine. Is this something that would contribute in any amount to low oil pressure?

That's a common failure. And no, It won't cause low oil pressure as long as if the check valve is working properly.