LS3 Oil Pressure
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 832
Likes: 14
From: Lake Charles Louisiana
LS3 Oil Pressure
I've read for hours and still haven't seen anything solid. So, here we go.
Purchased a used 2011 LS3 with no background info other than it had roughly 30k miles.
Purchased used as a short block. I did NOT disassemble the bottom end as everything felt tight and everything I saw indicated a very low mileage motor as it was advertised.
Cam bearings looked excellent.
Installed a new Melling 10296. Heavy spring installed. Did NOT shim with feeler gauges upon install. Did NOT pinch O-ring. Engine on stand, assembly lube used. Not even a remote chance of it being the O-ring.
New valley cover. New pickup tube. SacCity barbell installed. Everything assembled correctly.
New oil pressure sensor. Checked 2 for verification. Two dash clusters that read identical. Have NOT ran manual pressure gauge. Two sensors, two clusters agree to the pound.
Johnson 2116LSR lifters.
20-50 Mobil 1.
50 degree oil:
Pressure at start up 800 RPM idle: 50 psi.
Pressure at 2000 RPM: 62 psi.
Pressure at 3000 RPM: 70 psi.
Pressure at 4000 RPM: Buries the gauge at 80 psi.
195 degree oil:
Pressure at 800 RPM idle: 17 psi
Pressure at 2000 RPM: 30 psi
Pressure at 3000 RPM: 35 psi
Pressure at 4000 RPM: 43 psi and tops out at about 45 psi.
No noises from the motor at any RPM range.
I know the GM specs and these numbers fall in there but in past experiences with several LS1's and Melling 10296 pumps these numbers are WAY off. My Vette with a 10296 and 125k on the clock still cold start idles, around 50 degrees, around 68 psi, hot idles at 46 psi and 2000 RPM on the highway at about 63 psi.
I just had Precision Pumps port and polish a 10365HV for this thing and it's ready to install but if I tear the front apart and swap it out and see similar numbers I'm not going to be happy.
Please, all comments are welcome but those with LS3 experience step up to the front.
Thanks.
Purchased a used 2011 LS3 with no background info other than it had roughly 30k miles.
Purchased used as a short block. I did NOT disassemble the bottom end as everything felt tight and everything I saw indicated a very low mileage motor as it was advertised.
Cam bearings looked excellent.
Installed a new Melling 10296. Heavy spring installed. Did NOT shim with feeler gauges upon install. Did NOT pinch O-ring. Engine on stand, assembly lube used. Not even a remote chance of it being the O-ring.
New valley cover. New pickup tube. SacCity barbell installed. Everything assembled correctly.
New oil pressure sensor. Checked 2 for verification. Two dash clusters that read identical. Have NOT ran manual pressure gauge. Two sensors, two clusters agree to the pound.
Johnson 2116LSR lifters.
20-50 Mobil 1.
50 degree oil:
Pressure at start up 800 RPM idle: 50 psi.
Pressure at 2000 RPM: 62 psi.
Pressure at 3000 RPM: 70 psi.
Pressure at 4000 RPM: Buries the gauge at 80 psi.
195 degree oil:
Pressure at 800 RPM idle: 17 psi
Pressure at 2000 RPM: 30 psi
Pressure at 3000 RPM: 35 psi
Pressure at 4000 RPM: 43 psi and tops out at about 45 psi.
No noises from the motor at any RPM range.
I know the GM specs and these numbers fall in there but in past experiences with several LS1's and Melling 10296 pumps these numbers are WAY off. My Vette with a 10296 and 125k on the clock still cold start idles, around 50 degrees, around 68 psi, hot idles at 46 psi and 2000 RPM on the highway at about 63 psi.
I just had Precision Pumps port and polish a 10365HV for this thing and it's ready to install but if I tear the front apart and swap it out and see similar numbers I'm not going to be happy.
Please, all comments are welcome but those with LS3 experience step up to the front.
Thanks.
Safety Car
Joined: May 2011
Posts: 3,807
Likes: 508
From: Oshawa, Ontario
Some of the after market lifters have a smaller outside diameter than the GM lifters and will lose some oil pressure because of this.Compare the outside diameter of the ones your using and the GM ones.Why such a heavy weight oil (20w50) in a stock engine? With a stock pump and hot idle I have never seen my oil below 42 psi.At 4,000 plus rpm mine is over 70 psi
Last edited by irok; Apr 2, 2020 at 11:18 AM.
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 832
Likes: 14
From: Lake Charles Louisiana
Started with lower weight oil. Pressure was down to about 15 hot idle. Went up to 20-50 to get it to 17.
I do think there may be a difference in lifter diameter. That may be part of the problem just can't wrap my head around there being that much loss of pressure due to that alone.
I do think there may be a difference in lifter diameter. That may be part of the problem just can't wrap my head around there being that much loss of pressure due to that alone.
Safety Car
Joined: May 2011
Posts: 3,807
Likes: 508
From: Oshawa, Ontario
Have seen several threads over the years on here of owners complaining of loss of oil pressure after switching to smaller diameter after market lifters.Check on line for diameter of lifters you are using versus GM lifters.I use GM racing lifters that are rated for 8,000 rpm
Instructor
Joined: Nov 2002
Posts: 143
Likes: 0
From: Big WA
Your 2116 lifters don't have axle oiling but I am planning to use the 2126 version with axle oiling which are reported to reduce oil pressure a bit. This info was posted on the other forum.
Spoke with Joe at Johnson Lifters.
* When setting pre-load in the engine, sometimes the oil pre-installed in the lifter from the factory will seep out, and it's important to have a thin oil in the engine during startup to ensure it gets into the lifters, something like a cheap 30 weight.
* They have people using 20W-50 oil with these lifters
* Axle oiling may reduce oil pressure by 3-5psi
* Excessive lifter bore clearance will also lower oil pressure
* Lifter diameter is .8418-.8422, desired lifter bore clearance is .0015-.0020
* Set pre-load, find 0 lash, then (for aluminum engines) add .0035 to pushrod length
* That should set preload to ~.0020 when hot
* Max valvespring pressures confirmed to work with the lifter is 185 seat, 530 open
Spoke with Joe at Johnson Lifters.
* When setting pre-load in the engine, sometimes the oil pre-installed in the lifter from the factory will seep out, and it's important to have a thin oil in the engine during startup to ensure it gets into the lifters, something like a cheap 30 weight.
* They have people using 20W-50 oil with these lifters
* Axle oiling may reduce oil pressure by 3-5psi
* Excessive lifter bore clearance will also lower oil pressure
* Lifter diameter is .8418-.8422, desired lifter bore clearance is .0015-.0020
* Set pre-load, find 0 lash, then (for aluminum engines) add .0035 to pushrod length
* That should set preload to ~.0020 when hot
* Max valvespring pressures confirmed to work with the lifter is 185 seat, 530 open
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 832
Likes: 14
From: Lake Charles Louisiana
Your 2116 lifters don't have axle oiling but I am planning to use the 2126 version with axle oiling which are reported to reduce oil pressure a bit. This info was posted on the other forum.
Spoke with Joe at Johnson Lifters.
* When setting pre-load in the engine, sometimes the oil pre-installed in the lifter from the factory will seep out, and it's important to have a thin oil in the engine during startup to ensure it gets into the lifters, something like a cheap 30 weight.
* They have people using 20W-50 oil with these lifters
* Axle oiling may reduce oil pressure by 3-5psi
* Excessive lifter bore clearance will also lower oil pressure
* Lifter diameter is .8418-.8422, desired lifter bore clearance is .0015-.0020
* Set pre-load, find 0 lash, then (for aluminum engines) add .0035 to pushrod length
* That should set preload to ~.0020 when hot
* Max valvespring pressures confirmed to work with the lifter is 185 seat, 530 open
Spoke with Joe at Johnson Lifters.
* When setting pre-load in the engine, sometimes the oil pre-installed in the lifter from the factory will seep out, and it's important to have a thin oil in the engine during startup to ensure it gets into the lifters, something like a cheap 30 weight.
* They have people using 20W-50 oil with these lifters
* Axle oiling may reduce oil pressure by 3-5psi
* Excessive lifter bore clearance will also lower oil pressure
* Lifter diameter is .8418-.8422, desired lifter bore clearance is .0015-.0020
* Set pre-load, find 0 lash, then (for aluminum engines) add .0035 to pushrod length
* That should set preload to ~.0020 when hot
* Max valvespring pressures confirmed to work with the lifter is 185 seat, 530 open
Racer
Joined: May 2017
Posts: 429
Likes: 71
If i was you, through process of elimination if you have factory style lifters around, i'd throw them on and see what oil pressure ends up being. You'll be burning a pair of head gaskets and some time but that might be one of the simpler things to do before tearing the motor back apart. I get it, it might not be your problem but I'm not sure what your other options are first.
Last edited by rsb213; Apr 3, 2020 at 12:01 AM.
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Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
Yeah, something seems off with that kind of pressure difference between hot and cold. Johnson lifters are known to drop oil pressure though. I have their 2110 drop-in lifters in my car with the same Melling HV 10296 pump with the high-pressure spring (which came installed in my pump, iirc) which I did take the time to install using feeler gauges, per Melling’s instructions, and I now get 50psi at 800rpm cold and it drops by about 10 psi when it’s hot. I can’t remember what the hot idle pressure was when I was running Mobil 1 5W-30, bit it was pretty low, which is why I’m currently running Mobil 1 0W-40 (because I really think 20W-50 is too thick on start=up on these motors).
Last edited by CI GS; Apr 3, 2020 at 08:15 PM.
Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
I’ll try to look up some old logs and see if can get some better info for you.
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 832
Likes: 14
From: Lake Charles Louisiana
Melting Slicks
Joined: Feb 2007
Posts: 3,297
Likes: 398
From: Raleigh Suburbs
Then conversely, when it heats up you are back down relatively speaking, makes sense.
So, the overall lowness of the readings, based on the information in this thread, is your lifters ? Makes sense, seems to be the only variable, you might be right at the normal psi readings for the setup.
Hmm interesting..
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 832
Likes: 14
From: Lake Charles Louisiana
Just thinking out loud here, however, with the thicker oil, you are getting high psi readings when cold, makes sense, that's like a racing oil!
Then conversely, when it heats up you are back down relatively speaking, makes sense.
So, the overall lowness of the readings, based on the information in this thread, is your lifters ? Makes sense, seems to be the only variable, you might be right at the normal psi readings for the setup.
Hmm interesting..
Then conversely, when it heats up you are back down relatively speaking, makes sense.
So, the overall lowness of the readings, based on the information in this thread, is your lifters ? Makes sense, seems to be the only variable, you might be right at the normal psi readings for the setup.
Hmm interesting..
I really can't find a lot of info on the 365HV to compare it pressure, and volume wise, to the 10296.
1st Gear
Joined: Mar 2022
Posts: 1
Likes: 0
I've read for hours and still haven't seen anything solid. So, here we go.
Purchased a used 2011 LS3 with no background info other than it had roughly 30k miles.
Purchased used as a short block. I did NOT disassemble the bottom end as everything felt tight and everything I saw indicated a very low mileage motor as it was advertised.
Cam bearings looked excellent.
Installed a new Melling 10296. Heavy spring installed. Did NOT shim with feeler gauges upon install. Did NOT pinch O-ring. Engine on stand, assembly lube used. Not even a remote chance of it being the O-ring.
New valley cover. New pickup tube. SacCity barbell installed. Everything assembled correctly.
New oil pressure sensor. Checked 2 for verification. Two dash clusters that read identical. Have NOT ran manual pressure gauge. Two sensors, two clusters agree to the pound.
Johnson 2116LSR lifters.
20-50 Mobil 1.
50 degree oil:
Pressure at start up 800 RPM idle: 50 psi.
Pressure at 2000 RPM: 62 psi.
Pressure at 3000 RPM: 70 psi.
Pressure at 4000 RPM: Buries the gauge at 80 psi.
195 degree oil:
Pressure at 800 RPM idle: 17 psi
Pressure at 2000 RPM: 30 psi
Pressure at 3000 RPM: 35 psi
Pressure at 4000 RPM: 43 psi and tops out at about 45 psi.
No noises from the motor at any RPM range.
I know the GM specs and these numbers fall in there but in past experiences with several LS1's and Melling 10296 pumps these numbers are WAY off. My Vette with a 10296 and 125k on the clock still cold start idles, around 50 degrees, around 68 psi, hot idles at 46 psi and 2000 RPM on the highway at about 63 psi.
I just had Precision Pumps port and polish a 10365HV for this thing and it's ready to install but if I tear the front apart and swap it out and see similar numbers I'm not going to be happy.
Please, all comments are welcome but those with LS3 experience step up to the front.
Thanks.
Purchased a used 2011 LS3 with no background info other than it had roughly 30k miles.
Purchased used as a short block. I did NOT disassemble the bottom end as everything felt tight and everything I saw indicated a very low mileage motor as it was advertised.
Cam bearings looked excellent.
Installed a new Melling 10296. Heavy spring installed. Did NOT shim with feeler gauges upon install. Did NOT pinch O-ring. Engine on stand, assembly lube used. Not even a remote chance of it being the O-ring.
New valley cover. New pickup tube. SacCity barbell installed. Everything assembled correctly.
New oil pressure sensor. Checked 2 for verification. Two dash clusters that read identical. Have NOT ran manual pressure gauge. Two sensors, two clusters agree to the pound.
Johnson 2116LSR lifters.
20-50 Mobil 1.
50 degree oil:
Pressure at start up 800 RPM idle: 50 psi.
Pressure at 2000 RPM: 62 psi.
Pressure at 3000 RPM: 70 psi.
Pressure at 4000 RPM: Buries the gauge at 80 psi.
195 degree oil:
Pressure at 800 RPM idle: 17 psi
Pressure at 2000 RPM: 30 psi
Pressure at 3000 RPM: 35 psi
Pressure at 4000 RPM: 43 psi and tops out at about 45 psi.
No noises from the motor at any RPM range.
I know the GM specs and these numbers fall in there but in past experiences with several LS1's and Melling 10296 pumps these numbers are WAY off. My Vette with a 10296 and 125k on the clock still cold start idles, around 50 degrees, around 68 psi, hot idles at 46 psi and 2000 RPM on the highway at about 63 psi.
I just had Precision Pumps port and polish a 10365HV for this thing and it's ready to install but if I tear the front apart and swap it out and see similar numbers I'm not going to be happy.
Please, all comments are welcome but those with LS3 experience step up to the front.
Thanks.
Pro
Joined: Mar 2022
Posts: 547
Likes: 153
One other thing ive heard is oil pressure gauges vary WILDLY, up to 10+psi, so we could be running a bad batch at actual 25 without a problem and without knowing. Need to get a mechanical gauges on it to test this theory.