the add to quarts of oil test? has it worked for anyone?

[j91z28d1]

only really reading up on this Gen engines now and don't want to hijack another thread.
it makes sense and I see it recommended a lot, has anyone done it and it raised oil pressure? if so, how much?

I only ask out of curiosity. mine is an 11 with 145k has really high oil pressure, but being a different style oil pump it doesn't really count, the spec is much higher too and my other ls based engine I have now is a ls3. it's got 110k ish on it, I just had the pan off it to inspect bearings, for another reasons(blown oil line during a truck day) and changed out the o ring, it was a blue one. and it was super soft and it looked exactly like the new oem one I put in. I did have a 02 z28 years ago I put a ton of hard miles on and never changed oil till it said to, and used cheap bulk oil in whatever weight I had access to. (back in the broke kid days haha ran 87 in that poor thing all the time too haha) never noticed oil pressure change over the life of it.

just leaves me wondering what gm did with all these truck o rings that they fail so often. especially when the factory spec for oil pressure is called out to be so low that like 10psi hot idle is considered fine by it. how much of a drop is normal that leads guys to this board searching for reasons?

 

[OR VietVet]

If you have "high" oil pressure now and are experiencing no concerns, if the norm drops an uncomfortable level, that is when you start worrying. Then you search for the answer. Lot's of threads here about oil pressure concerns and sounds like you have been reading them. Whatever led the OP to post about an oil pressure concern, that is what you look for too.

 

[j91z28d1]

I'm just reading the threads cause it's interesting, I'm asking cause I have nothing to compare to. mine has a variable displacement pump, and much higher oil pressure than a normal truck. so mine doesn't tell me anything useful about others. just to be clear, my truck is fine. I'm not asking for me. it's more I've been a maintenance mechanic most of my life and have a general curiosity about it.

the threads I have seen pretty much have no info, I haven't seen any that said what their oil pressure was before and then what it dropped to now that caused their concern. usually the question is asked, but by then the thread is dying off and there's no reply. same with the add oil tests. I see it said to do it, but not seen anyone do it and report back that it helped.

this is all just random curiosity on my part. I'm not saying anything is wrong or not just see guys that have been on here a lot longer answering questions and wondering if they have seen a bunch of cases of the adding oil working? I caught a comment of a member ran his over filled a year or so before he could fix it and it left me wondering how often it works.

I haven't scrolled back to far in time, has there been many posts that ended up hurting bearings from low pressure or is it more the low pressure kills the afm lifters first?

 

[Dustin Jackson]

Here is a braindump of my observations.

GMT800 - Can have lifter failure, usually caused by lifters turning in the plastic tray, these lifters can eat the cam when turned and damaged. I see some threads on oil pressure concerns but like you said they usually have no conclusion, I suspect that is because these motors can survive on very little oil pressure and the motor keeps running (and the OP doesn't post because they stopped worrying) or they have money to spend and buy a new motor or rebuild it.

GMT900 - Introduces the AFM system and basically every point of the system has the potential to leak oil pressure or outright fail. Lifters now have more ways they can fail, VLOM malfunctions contributing to oil pressure loss and lifter failure. AFM system eats lifters and cams. You see alot of threads about low oil pressure concerns, some threads they are able to improve their oil pressure by replacing the o-ring or throwing their purse at it but 99.99% of the threads leave the user unsatisfied with what their oil pressure gauge reads. I suspect this has to do with the oil pressure sensors in circulation. When I did my AFM delete I replaced my oil pressure sensor while I had the motor open and my oil pressure gauge doesn't read the same as it used to and I think it is just the oil pressure sensor I used.

I think the oil pressure gauge these days is unreliable and is not fulfilling the purpose that users are relying on it to do. Also I have heard people say "every chevy I've owned has never dropped below 40PSI oil pressure so you engine is ******".

The only oil pressure gauge I can trust is my ear, I listed to the motor and if it doesn't sound like someone is stirring a silverware drawer I send it, I've done this for all my vehicles. I had 1 Dodge 5.9 with a dying motor due low oil pressure after someone rebuilt it wrong and it sounded terrible so I know what low oil pressure sounds like, I understand a lot of people haven't had that experience but they try to trust their cluster and it disappoints them.

 

[j91z28d1]

that makes sense. the afm does seem to be a good way to lose pressure.

I still not sure the "oem" Amazon sensor is correct. enough that I'm changing the 2nd one I got from them out soon most to see.

so what is the average pressure for say a good running 50k mile 5.3 with the afm vvt stuff warm on the 5w30? I know the gm spec is very low before they consider it a problem but what's real world when everything is still tight. also these things seem to idle in gear at like 600rpm. that's not much to ask for 40psi warm


I do also agree that ls engines, at least the bottom end doesn't need much oil pressure, if you ever follow sloppy mechanic, he does the grab a junk yard 5.3, stick it in a car with a big turbo, run e85 and don't replace anything type builds. he has gone 8s in the 1/4 with a 4.8 that idles at 10psi oil pressure. now no afm to keep alive, but that's a lot of load on the bottom end, if these engines needed a ton of oil pressure, he would kick a rod out by the 60 foot mark lol.


my ls 3 blew a oil line deep into a session, oil Temps above 250 at the time, and I didn't know it happened till I hit the brakes and went for a ride. looking back at the oil trail, it happened early in 2nd, so full wot pull in 2nd, shift to 3rd and full pull to almost redline, lift off throttle full engine braking and a down shift to 2nd as I hit the brakes and went for a spin. come to a stop, pull off the track and kill the engine. it was a main oil cooler line so none or very little oil went to the engine. I guess some would, but I'm guessing next to no pressure.

I figured bearings were toast at least if not cam. pulled the pan, check bearings and bearly even a scratch. I've seen new bearings look worse after checking with plastic gauge lol.

so yeah, I don't think atleast the bottom end of a low rpm daily driver needs a ton of pressure to survive. it does leave me wondering why the hybrid has such a different oil pump and pressure spec thou. it's basically the same thing. just starts a million times more over its life haha.

 

[Foggy]

1st of all: lots of fake/counterfeit parts out there... IDK if amazon is the best source...
and these gauges are just a guideline at best, esp the coolant temp...
2nd: the actual "TEST" that OP is asking about basically drowns the oil pump inlet
in oil and ONLY is an indication of the condition of the oil pump inlet tube pick-up O RING only.

The test is: add 2 quarts extra to an already warmed up engine. Park downhill (pretty decent
grade is needed for oil to slosh to front of pan)
Don't rev engine.. IF you see a significant increase in oil pressure on your gauge or scanner,
then you prob have at least a deteriorated O-RING (you may have other issues too)
But this test is only for the O Ring.
Then, don't drive around with the extra oil... Get it to the correct level immediately or you'll
be dealing with way more issues soon enough

 

[swathdiver]

just leaves me wondering what gm did with all these truck o rings that they fail so often.

This is not true. When the o-ring gets brittle is when they fail and then they good for another similar duration of about 165K miles.

What does "really high oil pressure" mean? Gen IV LS engines come in an aluminum and iron block variety. Each has a different pump and pressure bypass spring.

Increasing a healthy engine's pressure is usually a waste of horsepower and gas mileage unless one is racing it and even then my own experience was to leave a good thing alone.

Which engine is in your 2011? What kind of car is your LS3 in?

 

[iamdub]

mine has a variable displacement pump,

It does?

and much higher oil pressure than a normal truck.

What PSI? According to the gauge on the dash?

the threads I have seen pretty much have no info, I haven't seen any that said what their oil pressure was before and then what it dropped to now that caused their concern. usually the question is asked, but by then the thread is dying off and there's no reply. same with the add oil tests. I see it said to do it, but not seen anyone do it and report back that it helped.

I wanna say there has been at least two within the past year where they reported the results of the overfill and nosedive test. IIRC, one had an immediate rise in PSI and the other had no difference.

 

[iamdub]

just leaves me wondering what gm did with all these truck o rings that they fail so often.

They really don't fail so often. It's an age thing. The O-ring loses elasticity, shrinks, gets brittle and splits. It's in a rather harsh environment of chemicals and temperature swings. They commonly last well over 150K miles.

It IS a common failure in higher-mileage engines and that's when you see posts about testing it.

 

[donjetman]

Mine at 130k miles w/good oil pressure. Broke when I pulled it off.

 

[j91z28d1]

Mine at 130k miles w/good oil pressure. Broke when I pulled it off.
View attachment 397081

I have see that a lot over the years, a o ring that's fine, till you pull it off and try to take it off. it then splits. not on these trucks, just general stuff I work on.

I wonder if gm only putting the one bolt on let's the tube move around enough for the o rings to break while still inside their groove

 

[j91z28d1]

by higher oil pressure this is what I mean, what gm calls out as acceptable. I'm still not sure what you actually see in the gauges?


*see attached*
so basically it says 22psi at 1000rpm and doesn't set a engine light till 15 ish. I'm guessing by a 600rpm idle that would be 10ish?


the spec for the 08-13 6.0 hybrid with the variable displacement pump calls for a different spec.
oil pressure spec hot
36psi @1000
42psi @2000
45psi @4000
afm relief valve 55-75 max.
p0521 ecm detects different oil pressure than expected by lower 6.8psi or greater than 7.3 psi for 10sec

seems like a big difference in pressures for basically the same engine. that's all I meant by that comment. it doesn't really idle when it's hot, it auto stops, I'd have to see force it to run and see what it idles at. but any time it comes out of auto stop it goes straight to the mark between 40 and 80. you've got me curious. I'll have to check. I've never noticed it below 40psi. I've got a legitimate dealer bought new sender on it. I agree there seem to be some counterfeit ACDELCO parts on Amazon. they got me the 1st time.

I'm still wondering what a standard 5.3 idles at when hot in a low mileage one?


my ls3 is in a c6. on 5w30 at 200deg temp it is around 38psi.(no afm or vvt) but that's a manual idling at either 750 or 800rpm. I can't remember now, bumped it up a few rpm at idle for the alternator voltage after I put a underdrive balancer on it. so not really applicable, I only mentioned it because it's over 100k and I've had it above 300deg oil Temps a few times at the track and mountains before I got the Temps under control and just changed the o ring out cause I was in there. it was the original one, blue color for the sizing but it was perfect. couldn't tell a difference between it and the new one I got from the dealer to replace it.

 

[j91z28d1]

I wanna say there has been at least two within the past year where they reported the results of the overfill and nosedive test. IIRC, one had an immediate rise in PSI and the other had no difference.

do you happen to remember the how much different it made on the one that it improved?

 

[j91z28d1]

This is not true. When the o-ring gets brittle is when they fail and then they good for another similar duration of about 165K miles.

What does "really high oil pressure" mean? Gen IV LS engines come in an aluminum and iron block variety. Each has a different pump and pressure bypass spring.

Increasing a healthy engine's pressure is usually a waste of horsepower and gas mileage unless one is racing it and even then my own experience was to leave a good thing alone.

Which engine is in your 2011? What kind of car is your LS3 in?

I agree that normally running higher oil pressure than needed, like a high volume high pressure pump on a stock engine will waste hp. in fact millings recommens not increasing either one unless there's a need over stock levels.

funny thing is, everything I read says the veritable displacement pump saves 1.5hp but seem the spec is higher pressure. I didn't think about the aluminum block to iron, they do grow more when hot. not sure if they run a smaller starting main bearing clearance compared to the iron.

only because I just looked it up inspecting my other one, the aluminum ls3 min mains are 0.0008 and even my every so slightly worn ones where at 0.001.(not that I can measure that small of an amount consistently with my tools, but I tried lol.) which would be super tight for a iron block.

wonder if they left the mains loose on this aluminum 6.0 and just over volumed the pump. I'll have to look at the min and max spec later and compare to a iron 5.3

 

[swathdiver]

I agree that normally running higher oil pressure than needed, like a high volume high pressure pump on a stock engine will waste hp. in fact millings recommens not increasing either one unless there's a need over stock levels.

funny thing is, everything I read says the veritable displacement pump saves 1.5hp but seem the spec is higher pressure. I didn't think about the aluminum block to iron, they do grow more when hot. not sure if they run a smaller starting main bearing clearance compared to the iron.

only because I just looked it up inspecting my other one, the aluminum ls3 min mains are 0.0008 and even my every so slightly worn ones where at 0.001.(not that I can measure that small of an amount consistently with my tools, but I tried lol.) which would be super tight for a iron block.

wonder if they left the mains loose on this aluminum 6.0 and just over volumed the pump. I'll have to look at the min and max spec later and compare to a iron 5.3

Do you have a Gen IV Hybrid 6.0 motor? Those and the newer LT engines have the variable displacement oil pumps. Yes, the aluminum blocks have more open tolerances once warmed up, that's why their pumps are spec'd to pump 1/3 more oil per revolution and run with a lower bypass spring, in the 30s. All my trucks run with oil pressure in the upper 30s while cruising down the highway.

An LC9s crankshaft main bearing clearance in production is .0008-.0021 and to .0025 in service. Definitely tough to see! Now with my old eyes it'll have to be "close enough for tv"!

 

[iamdub]

.I wonder if gm only putting the one bolt on let's the tube move around enough for the o rings to break while still inside their groove

I've seen the kits to add a bolt to the other side. But I'm just not buying that it's a problem if the tab on the tube or the tube itself isn't bent out of shape and correct hardware is used and torqued properly. The other end of the tube is bolted to one of the studs on the windage tray.

 

[j91z28d1]

yeah it's a 2011 hybrid. I've seen a tear down of the new LT oil pump and it's totally different. much larger and would not even fit these Gen 4. I've yet to see one of these in person. just the part number. seems millings has a listing as well as the oem gm. unless they made the pump for gm.

but it is said to fit in any ls block. I've seen them talked about on the corvette boards because of the hp savings.


upper 30s cruising at I'd guess under 2k? that seems like good oil pressure to me. do you happen to know what it idles at out of curiosity? at what point would you be concerned it was to low?

if I get time tomorrow, I'm going to hook up a scanned and force mine to not auto stop and see what it idles at warm.

not that has anything to do with my original post, but yeah. kind of an off topic oil pump post at this point anyways.

 

[j91z28d1]

I've seen the kits to add a bolt to the other side. But I'm just not buying that it's a problem if the tab on the tube or the tube itself isn't bent out of shape and correct hardware is used and torqued properly. The other end of the tube is bolted to one of the studs on the windage tray.

yeah, I forgot it was bolted to a main stud. I do remember listening to this a while back while mowing the yard, and one of the questions at the end Q&A was if the cheap little add one extra pipe hold down was worth doing, and if I remember right, they said yes for the cost, it's cheap insurance and might be some movement at high rpm vibrations.

 

[iamdub]

by higher oil pressure this is what I mean, what gm calls out as acceptable. I'm still not sure what you actually see in the gauges?

LOL @ what GM calls out as acceptable, especially on the subject of oil consumption.

*see attached*
so basically it says 22psi at 1000rpm and doesn't set a engine light till 15 ish. I'm guessing by a 600rpm idle that would be 10ish?

Thankfully, it's not so linear. Mine hot idles around 650 and 25-27 PSI. 1,000 RPM takes it to mid-30s. 2,000 RPM is good for around 42 PSI. My guess is that one, at hot idle, would be around 20 PSI.

the spec for the 08-13 6.0 hybrid with the variable displacement pump calls for a different spec.
oil pressure spec hot
36psi @1000
42psi @2000
45psi @4000
afm relief valve 55-75 max.
p0521 ecm detects different oil pressure than expected by lower 6.8psi or greater than 7.3 psi for 10sec

I didn't know you had a Hybrid nor did I know it had a variable displacement pump. I only knew of GenV engines having them. I also just realized my pressures are spot-on with the Hybrid specs. Mine's a 222K-mile LMG with a high volume pump (Melling M295HV, also ported),
plugged AFM towers and plugged AFM relief valve port.

seems like a big difference in pressures for basically the same engine. that's all I meant by that comment.

I see what you mean now. Yeah, those spec'd pressures do seem higher than the non-Hybrid engines. I think they allow low-20s at hot idle and under 40 cruising (1500-2000). Still plenty.

I'm still wondering what a standard 5.3 idles at when hot in a low mileage one?

I think they varied wildly from the factory. Mine, at 200K when it was still stock was around 3-5 PSI lower average across the board from where it is now.

 

[iamdub]

do you happen to remember the how much different it made on the one that it improved?

I don't remember. They might not have even specified. A lot of "non-established" members tend to vanish after getting the answers they seek and this might've been one. But, they were also one of the few that reported back. All I remember was that they said something about their pressures immediately improving so now they know their oil pressure issue was due to the O-ring.

The low pressure caused by a failed O-ring can vary in significance. It could be slight split that just allows a little air in and it could even be intermittent due to temperature. So the pressure starts out fine then drops or starts outs low then stabilizes. It could also be brittle and cracked at multiple points, causing a big leak, preventing the pump from priming.

The test is conclusive either way. By submerging that point in oil, the O-ring is taken out of the equation. It's not gonna make the pressure higher than it'd be if the O-ring was good. It just makes the pressure where it would be if the O-ring wasn't bad.