Oil Pressure - Am I paranoid?

pbbigmac2 · Friday at 7:18 PM

A little background- bought my Yukon XL with 145k miles, 1 year old jasper engine installed at 130k. Changed oil maximum every 5k with 5w-30 and OEM filter. Replaced the oil pressure sensor at some point during my ownership and always kept an eye on it.

18 months later, family took an ~800 mile trip and came back with a stuck rocker arm that resulted in a new engine under warranty at 166k.

Paid extra for them to ship a new non-afm engine, but the oil pressure still seems extremely low considering it should only decrease further with wear.

I have attached OBD2 scanner data of RPM values and oil pressure readings. Don’t think I captured cold idle, but it’s north of 50psi.

Am I over focused on this? Should I try a new sensor or hook it up to a mechanical gauge for reassurance?

Marky Dissod · Friday at 7:30 PM

None of us will be able to assuage your fears as well as a mechanic, even though we're cheaper.

Those don't look 'too' low, but I get it.

Just before you're about to do an oil change, get your engine up to operating temp, then park it with the nose down (front tires at least 2ft under rear tires).
Add two quarts of oil. If oil pressure improves, you must replace your old@$$ oil pump pickup O-ring. If not, it's something else.
Either way, drive like you've several broken bones in your right foot after adding those two extra quarts until you drain them out; hurry up and drain them out.

pbbigmac2 · Friday at 7:51 PM

I had that suspicion with the previous engine, however a brand new reman engine should also likely have a brand new pick up o-ring.

Marky Dissod · Friday at 8:09 PM

pbbigmac2 said:
I had that suspicion with the previous engine, however a brand new reman engine
SHOULD!
also likely have a brand new pick up o-ring.

Trust, then verify anyway?

j91z28d1 · Friday at 8:16 PM

12psi at hot idle is technically within gm. spec. but that does seem pretty low for a fresh engine?

if I remember right you're in Co? if so, should be pretty easy to find a steep. hill to face down and see if the oil. pressure goes up as the oil moves forward and covers the oring.

I would. also guess it wouldn't, but if it's easy enough to try, why not

pbbigmac2 · Friday at 8:21 PM

I’m in VA, but I’m sure I can test it before it’s due for its 500 mile change.

j91z28d1 · Friday at 8:29 PM

pbbigmac2 said:
I’m in VA, but I’m sure I can test it before it’s due for its 500 mile change.

ahh, my memory is old. must have been a different jasper engine guy that got a 2nd when the first failed.

you don't need to add the extra oil if the hill or drive way is steep enough.

Chughart · Friday at 10:02 PM

id contact jasper and atleast start a case with them so its on record. not that you want to hear this but i had some issues with oil pressure on my jasper engine as well (made it about 20k miles) . contacted them and sent them the oil pressure readings and they sent me a new engine (afm deleted by them). i then had a lifter noise on the new engine and contacted them about it and they sent me "new" lifters. my advise would be to just contact them and go from there.

pbbigmac2 · Friday at 10:14 PM

Not what I want to hear, but I do appreciate the insight. Rather get this taken care of while still under their warranty cause, in 90 or so days, I’ll be SOL.

Chughart · Friday at 10:18 PM

did it not come with a 3 year 100k warranty? i will say when mines up to operating temp and at idle it sits right at 40 psi. when its cold its closer to 60psi. the gm spec is 10psi per 1000 rpm or something like that so youre within spec per gm but id still contact jasper and see what they say.

strutaeng · Friday at 10:25 PM

I think generally the human psychology wants to see "halfway mark" on the dummy guages. Otherwise we start wondering things...

12 psi at hot idle on a new crate engine does seem a bit low to me. We have a vehicle with the L96 6.0 and that one idles around 20 psi hot. It's got like 25K miles and we bought it with like 5k, so practically new, and it's always been like that.

I would call Jasper and see what they have to say. They may have the shop that installed the engine verify the pressure with a mechanical guage before anything.

pbbigmac2 · Friday at 11:23 PM

Chughart said:
did it not come with a 3 year 100k warranty? i will say when mines up to operating temp and at idle it sits right at 40 psi. when its cold its closer to 60psi. the gm spec is 10psi per 1000 rpm or something like that so youre within spec per gm but id still contact jasper and see what they say.

3years/100k warranty coverage begins when the original replacement is installed. Apparently, that does not reset when their engine does not survive past that point. So beginning Nov 2026, I will be on the hook.

Chughart · Friday at 11:47 PM

ya i knew that part. thats what they told me i just wasnt sure the timeline of your warranty.

lspann3525 · 2026-07-25T03:21:05-0400

cold idle mines goes a little bit over 40...hot idle I would say in the 30s..

I have noticed the longer I go without changing the oil the lower the oil pressure gets as I drive. But soon as I change the oil and filter the oil pressure gets better... I usually go by the oil percentage to change my oil but others change every 3k

Marky Dissod · 2026-07-25T09:56:14-0400

lspann3525 said:
the longer I go without changing the oil the lower the oil pressure gets as I drive. But soon as I change the oil and filter the oil pressure gets better.

That's how all motor oil works for everyone everywhere. However,
this happens to 5w20 more quickly than 5w30.

lspann3525 said:
I usually go by the oil percentage to change my oil but others change every 3k

Back when I had a 2012 Y-XL, I went by the Oil Life Monitor, SORT OF.
Mostly all highway miles (NOT NYC), change oil & filter by 25%, NEVER over 6000 miles.
More highway than local miles, change oil & filter by 33%, NEVER over 5000 miles.
More local than highway miles, change oil & filter by 41%, NEVER over 4000 miles.
Mostly all local miles (Manhattan, 5 boros, stop'n'go, LOTS of idling, also lots of restarts), change oil & filter by 50% - NEVER over 3000 miles.
Pretty much how NYC cabdrivers/chauffeurs treat the Oil Life Monitor.

With my '02 Tahoe, I change the oil every 3250-3500 miles.

Doubeleive · 2026-07-25T10:25:17-0400

pbbigmac2 said:
A little background- bought my Yukon XL with 145k miles, 1 year old jasper engine installed at 130k. Changed oil maximum every 5k with 5w-30 and OEM filter. Replaced the oil pressure sensor at some point during my ownership and always kept an eye on it.

18 months later, family took an ~800 mile trip and came back with a stuck rocker arm that resulted in a new engine under warranty at 166k.

Paid extra for them to ship a new non-afm engine, but the oil pressure still seems extremely low considering it should only decrease further with wear.

I have attached OBD2 scanner data of RPM values and oil pressure readings. Don’t think I captured cold idle, but it’s north of 50psi.

Am I over focused on this? Should I try a new sensor or hook it up to a mechanical gauge for reassurance?

some parts are re-used on a long block, I am not sure if the oil pump is one of them, or not the oil pan is for sure and I believe the oil pressure sensor is another and water pump and intake and the rest of the bolt on's, spark plugs should be new.
10 psi is the trigger for low oil pressure, technically 12 I would say is questionable, normally 14 is what you might see at hot idle.
at the very least when that 500 miles rolls around I would get a sample and send it out to blackstone labs or who ever you prefer.

Marky Dissod · 2026-07-25T10:35:13-0400

Doubeleive said:
10 psi is the trigger for low oil pressure, technically 12 I would say is questionable, normally 14 is what you might see at hot idle.

The Low Oil Pressure warning trigger threshold is a tune-able parameter in the ecm.
Also, it's not 'simply 10psi':

Here's a tuning suggestion:
RpM: 000 . . . 512 . . . 1024 . . . 1536 . . . 2048 . . . 2560 . . . 3072 . . . 3584 . . . 4096 . . . 4608 . . . 5120 . . . 5632 & Up
Min Psi tuned: 9.4 . . . . 11.2 . . . 13.1 . . . 15.0 . . . . 17.0 . . . 18.8 . . . . 19.6 . . . 20.7 . . . . 22.6 . . . 24.4 . . . 25.5

I'd not be surprised if it were possible to use this as a secondary Oil Life Monitor, monitoring shear/viscosity breakdown,
but I doubt most have the patience for this.

MD-Wood · 2026-07-25T10:43:04-0400

pbbigmac2 said:
A little background- bought my Yukon XL with 145k miles, 1 year old jasper engine installed at 130k. Changed oil maximum every 5k with 5w-30 and OEM filter. Replaced the oil pressure sensor at some point during my ownership and always kept an eye on it.

18 months later, family took an ~800 mile trip and came back with a stuck rocker arm that resulted in a new engine under warranty at 166k.

Paid extra for them to ship a new non-afm engine, but the oil pressure still seems extremely low considering it should only decrease further with wear.

I have attached OBD2 scanner data of RPM values and oil pressure readings. Don’t think I captured cold idle, but it’s north of 50psi.

Am I over focused on this? Should I try a new sensor or hook it up to a mechanical gauge for reassurance?

If its a gen 4 LS block that had DOD, it could be the valley cover and metal plugs they use to block off the old DOD. AT idle oil pressure is too low. your not wrong, its too low at idle.

Doubeleive · 2026-07-25T11:26:44-0400

Marky Dissod said:
The Low Oil Pressure warning trigger threshold is a tune-able parameter in the ecm.
Also, it's not 'simply 10psi':
View attachment 489993

Here's a tuning suggestion:
RpM: 000 . . . 512 . . . 1024 . . . 1536 . . . 2048 . . . 2560 . . . 3072 . . . 3584 . . . 4096 . . . 4608 . . . 5120 . . . 5632 & Up
Min Psi tuned: 9.4 . . . . 11.2 . . . 13.1 . . . 15.0 . . . . 17.0 . . . 18.8 . . . . 19.6 . . . 20.7 . . . . 22.6 . . . 24.4 . . . 25.5

I'd not be surprised if it were possible to use this as a secondary Oil Life Monitor, monitoring shear/viscosity breakdown,
but I doubt most have the patience for this.

I was wrong, while 10 psi is bad, 6 psi is what triggers the low oil pressure cel.
on mine it showed 10 on the cluster, while reading 6 or less (cam took a dump) and metal was stuck in the oil pump

lspann3525 · 2026-07-25T11:35:57-0400

I would throw an oil pressure sensor filter if it has one..those are known to throw off oil pressure

Oil Pressure - Am I paranoid?

Paranoid?

Drive it dummy

Take it to the shop

Need more info

TYF Newbie

Attachments

Full Access Member

TYF Newbie

Full Access Member

Full Access Member

TYF Newbie

Full Access Member

Full Access Member

TYF Newbie

Full Access Member

Full Access Member

TYF Newbie

Full Access Member

Full Access Member

Full Access Member

Wes

Full Access Member

TYF Newbie

Wes

Full Access Member

Similar threads

Forum statistics