Low(ish) Oil Pressure issues.

Bimmerjo said:

I wanted to chime in just really quick and say thank you for the replies. When I get a chance I'll sit down and reply individually. Thank you everyone for your input so far.

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This is just another example of why this Forum ROCKS!

Yes, indeed. There's actually a thousand times more info here than you'd ever get in a factory service manual. Such as areas in the wiring harness that are prone to have him broken wires.... And a little research on the forum can take you right to it. Been there and done that

OR VietVet said:

At that mileage, the small amount of glitter should be ok. BUT, small amount to me may not be to you. Bearing wear could be a concern.

Where in Mo.?

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Currently at 180k. I took a photo but they don't show up very well. I just did an oil change. When I cut the filter open, I found maybe 2-4 specs per pleat.

Located in Aurora.

OR VietVet said:

Might want to send an oil sample in for analysis.

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I just ordered a few bottles from Blackstone. That's the next step in this plan.

rdezs said:

1. AC Delco or genuine GM oil pressure sending unit was installed? If not, I'd take care of that first and also verify your oil pressure with a mechanical gauge. (Look online, you can pick up a tee fitting that goes under your oil pressure sending unit with a 1/8 NPT Port off to the side that you can hook a mechanical gauge into.... When done just install a 1/8 npt plug into the port)
2. Not sure if you have the oil pressure relief in the oil pan. Can't recall exactly when they started installing those. But if so, yes that's a possibility.
3. You're not in any danger zone yet, but it's good that you're noting the change in pressure.
4. Sending an oil sample in is always a good idea... Not just for this, but just for peace of mind at set intervals. I send one in every 20,000 miles.
5. With your mileage, I would suspect either the oil pump pressure relief is gummed up, or your front camshaft bearing is showing some wear.
6. As for the oil pump, it probably needs replaced at this mileage anyway.
7. As for the camshaft bearing up front, it's the one that wears out first. While many people on a budget have simply changed out that front bearing easily enough, nobody can really say how much time that buys you. If it's a camshaft bearing scenario, the correct course of action is to tear down the motor and do all the cam bearings.... At that point you're looking at rebuilding the whole motor. This is where the oil sample becomes quite valuable. It will tell you if you have a camshaft bearing on the way out. That oil sample can save you a lot of money on an unnecessary tear down. A lot of things to consider if it comes to that. Condition of the rest of the vehicle, do you plan on keeping it for years, budget, etc.

For what it's worth, when I tore into our 2014 Escalade last year at about 145,000 miles with similar oil pressure readings.... Needed to do the AFM delete anyway... When I disassembled the oil pump relief, I found several tiny pieces of grit in there and the plunger was hanging up.

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1: It was not. I don't recall what brand it was. I just redid intake manifold gaskets and that's when I replaced it. I probably went 10k without a working sending unit. I plan on getting a GM sensor from Rockauto when I order an oil pump hear soon.
Also, I'm not immediately finding a T fitting. Have a link by chance? I do plan on doing a relocation, just need to figure out how I would like to do it.
2. I believe the 6.2 blocks from the start have always been "provisioned" and setup for AFM. What I've learned is they didn't start putting the lifters and the valley cover oil circuitry in until they went to flex fuel. I think that was in 09, don't recall exactly.
3. Still close enough I want to get ahead of it.
4. See previous reply.
5-7. I appreciate the information. I will wait until I get results back from the sample and go from there.

j91z28d1 said:

being a non afm engine, I would guess there's no reason for the 2nd relief valve. if you ever have the pan off again, if it's even there. Just plug it.


I don't think you have anything to worry about. but I am curious about the glitter. as in how much, like a few specs? I have been cutting filters of random engines open over the last year or so and if you can get all the oil off the media. I lay it clean side down on pig mat and it sucks it dry over night. it's a bit surprising at first how many specs of metal you see. mostly sticks to a magnet too, which rules put some things that would commonly wear like piston side skirts. but you don't even see the stuff when it's still covered in oil and never seems to be an issues. the engines show no signs of failing. all mostly really high hour considered industrial stuff that runs 6 to 12h a day.

the gm low oil spec is crazy low and if you don't have afm. I wouldn't worry about it at all till you see under 10psi hot idle and then I'd probably still put some 10w40 in it and drive on haha.

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See previous reply. It's not needed. But a lot of the parts are there to get ready for it in future years.

donjetman said:

I have the same engine as you. Mine has 198k miles. We bought it road hard and hung up wet 6 yrs ago w/130k miles. It doesn't have an oil cooler.

All my hot pressures are the same as yours, which is normal.

First start of the day, anytime of the yr here in TX, it goes straight to 50-55psi at idle. This is probably the oil pump bypass/relief pressure. Oil filters also have a bypass in them.

In/on the oil pan is a afm pressure valve. I put a deflector ($8) on mine 6+ yrs ago per the GM TSB 10-06-01-008M:
https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf
and
https://www.tahoeyukonforum.com/thr...-tsb-10-60-10-008m.108493/page-2#post-1292730

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Appreciate the TSBs! Mine doesn't get that high at cold start up (32f). It'll cold idle now at 45psi. I'll explain later down this response as to why it increased from my previous readings.

BabushkinMechanic said:

I’ll put in my input, may answer some questions and someone may answer my questions.

I’ve changed out the oil sensor twice due to a leak and replaced o ring turned of AFM and replaced oil pan gaskets ect, and my oil pressure was still 16-20 hot idle. I finally caved in and put on a mechanical gauge with 15w-40 while the manifold was off. Mind you it’s a PPV with a lot of idle hours so bearing clearances are probably worn out by a lot. With oil cooler.

Oil pressure on the mechanical gauge right of the oil sensor hole read 24-25 psi hot. With 1-3 psi variances not flickering fast but slow up and down flickering between 1-2 sec or so.


Put it all back together with new sensor on.
The cluster gauge reads 16-20psi still, so i just ride on.

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I just replaced all the gaskets around the motor and I forgot to order the o rings where the valley cover meets the block for those oil circuits. When I tear back into it, I'm going to replace those as well. At least already having done that, it's fairly simple. I'm a deputy, so I understand just how much abuse your motor has been through.

rdezs said:

Cluster stepper motor if replacement sending unit reads the same. Drive on.

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While the change in readings is fairly lethargic, it always tries to show what live data is showing.

Joseph Garcia said:

This is just another example of why this Forum ROCKS!

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It really is quite the forum. I've been on forums since al gore created the internet and it's my favorite one.


I also wanted to give a quick update to something I discovered.

About a month ago, I dumped about 2k into it. I replaced every front suspension component. Ball joints and tie rod ends were mevotech and the front struts were replaced with genuine gm. (ouch). So far with replacing the rear air shocks and the fronts with genuine gm, it seriously rides like a brand new vehicle. I couldn't be happier. With that said, I replaced MOST of the gaskets around the motor. This includes the Valley cover, valve covers, front timing gasket and front main seal. Not sure what happened to the front main seal, but it ended up coming off when I pulled the crank shaft pully. As stated previously, I forgot to replace the orings where the valley cover meets the block so I'm going to replace those next time I tear into it. It'll likely be this spring.

Now, I've been running Fram Synthetic Endurance oil filters (I know their lower tier options are garbage). I used to run Wix but was having issues finding some. When I was picking up oil, I came across those at walmart. I found a couple of write ups on them that showed them to very well built. So I thought, hey, what the heck. Well... I still believe they're built very will but something I didn't notice until I put it side by side with an Ac delco filter, the inlet holes are TINY on the Fram compared to the AC Delco filter. Previous years that don't require high flow oil pump applications, this probably would have worked just fine. However, with the oil pumps now flowing a higher volume of oil for AFM and VVT, the tiny inlet holes just cant keep up. So with the fram, cold idle pressures were around 30 and would increase momentarily while the oil heated up (then come back down). The AC Delco cold idle pressures are 45. With fresh mobile 1 Advanced synthetic 10w-30 the hot pressures do still drop down to ~15psi. I've seen them on live data drop to 11psi when the AC cycles.

All of that to say, I'm going to send an oil sample to blackstone and see what the analysis shows. From there, I make a plan of action and report back. But I'll likely end up replacing oil pump and maybe the timing chain anyways.


Also... All of the filters that I have found are just absolutey tiny. Are there any larger ones that will fit this application correctly? I'm all for a higher oil capacity as well as more filter media surface area.

M16 x 1.5 is the thread size for the oil pressure sending unit. Below is an extension, which makes it easier to replace with the intake on, and also includes a 1/8 npt Port you can either block off or connect a secondary pressure gauge.

Stainless Steel M16 1.5 Oil Pressure Sensor Tee to 1/8 NPT Adapter for Turbo Supply Feed line Oil Pressure Gauge https://a.co/d/aUMlC76

@Bimmerjo
I've been running the Fram Ultra, Endurance, & Titanium (10575 & 10060) oil filters on all my L92 for 6 yrs, no issues, and my other cars for 15 yrs. I always cut them open and post pics (BITOG). I always post pics of my oil analysis reports too (BITOG).

It has come to my attention on BITOG forum that Fram changed ownership and the quality (materials & manufacturing) of their top tier filters has diminished. My research led me to the Purolator Boss PBL22500, it's 4.1" long and has a 22psi bypass.
or cross it over too
Premium Guard XL, Car Quest Premium (AAP), and MicroGard Select (O'Reilly's) are other brands of oil filters I'm considering.

rdezs said:

M16 x 1.5 is the thread size for the oil pressure sending unit. Below is an extension, which makes it easier to replace with the intake on, and also includes a 1/8 npt Port you can either block off or connect a secondary pressure gauge.

Stainless Steel M16 1.5 Oil Pressure Sensor Tee to 1/8 NPT Adapter for Turbo Supply Feed line Oil Pressure Gauge https://a.co/d/aUMlC76

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Just ordered. Thank you!

donjetman said:

@Bimmerjo
I've been running the Fram Ultra, Endurance, & Titanium (10575 & 10060) oil filters on all my cars for 6 yrs, no issues, I always cut them open and post pics (BITOG). I always post pics of my oil analysis reports too (BITOG).

It has come to my attention on BITOG forum that Fram changed ownership and the quality (materials & manufacturing) of their top tier filters has diminished. My research led me to the Purolator Boss PBL22500, it's 4.1" long and has a 22psi bypass.
or cross it over too
Premium Guard XL, Car Quest Premium (AAP), and MicroGard Select (O'Reilly's), other brands of oil filters I'm considering.

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That's another very good forum. Thanks for the number.

Another random thought that I had. If I were to go ahead and install the Melling 355HV pump, would it be advisable to install a new pressure relief valve in the pan? Or just go ahead and block it off?

Bimmerjo said:

Another random thought that I had. If I were to go ahead and install the Melling 355HV pump, would it be advisable to install a new pressure relief valve in the pan? Or just go ahead and block it off?

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If the TSB applies to your engine? do as it states, less than $10 (either way).