Low oil pressure at idle, pulling my hair out, looking for any and all options.

[mattbta]

On the cam choices, check out some Richard Holdener vids here: https://youtube.com/@richardholdener1727


He dyno tests a handful and seems to be pretty informative.

 

[Geotrash]

My rebuilder (ex) is adamant that the Cam Motion stage 2 is the exact same as the BTR Truck Norris, or so close that they would perform exactly the same. Pushed him to the back burner and talking to my other engine guy.

Good call to put that guy on the back burner. The BTR Truck Norris cam does NOT have the same specs as the Cam Motion Stage 2 truck cam. The lift and durations are very close but the difference is in the lobe separation angle. Truck Norris = 107 and the Cam Motion is 117. That's the difference between a ton of idle chop and a smooth idle. If chop is what you want, then go for it, but I had a choppy cam for a while and hated it for daily driving.

 

[Levin37]

So quick update; LS364/425 is ready for next week 8K Cdn delivered to my doorstep. Would still need to swap the cam and springs to match so add another G, and then $750 for a dyno tune but that's happening regardless. Might still go that way in the end but not now. Truck still drivable and has good power and pressure most of the time but it gets "stuck" and will only rumble along at like 80kph with no power and then not restart, like the timing is fully advanced(or retarded). So I've made the choice to just do a top end tear down, get the heads off and cam out, inspect the bearings. Bearings bad, pull the block for rebuild/swap, bearings good then new cam, VVT delete and new/rebuilt heads. Top end could use a refresh anyways and I believe the block to be solid for another 100k or so. I've gone ahead and ordered a pile of parts, like 5k worth, so I'm committed now. Used Geotrashs cam swap thread for a guideline, so props to him, it really helped me get my mind around things. Here's the list;

From Summit;
ARP 134-1202 - ARP Chromoly Header Bolt Kits
ARP 134-3610 - ARP Pro Series Cylinder Head Bolt Kits
ARP 234-2503 - ARP Balancer Bolts
Flotek LS3-500 - FLOTEK 276cc LS3 Cylinder Heads
Summit Racing SUM-8720-1 - Summit Racing™ Pro LS Camshaft & Spring
Summit Racing SUM-V8010-8 - Summit Racing™ Race Valves for Chevrolet
Trick Flow Specialties TFS-30678505 - Trick Flow® VVT Delete Combos

Michigan Motorsports (Ebay store)
5/16 7.400 Chromoly Pushrods
LS3 Rocker Arms with upgraded Trunion Kit Installed
Delphi LS7 Lifters and Guide Trays

Rock Auto
FEL-PRO 26192PT Cylinder Head Gasket
GM GENUINE 12569427 Intake Valve
GM GENUINE 12589016 Camshaft Gasket
GM GENUINE 12600936 Rocker Arm Shaft Support
GM GENUINE 12639759 Air Deflector

Amazon
MAHLE Original MS16124 Exhaust Manifold Gasket
ACDelco 252-901 Professional Water Pump
GM LS Harmonic Balancer Install Tool Pulley
Valve Spring Compressor Tool Compatible with GM
Lucas Oil 10153 Assembly Lube

Have a few more little parts and speciality tools to order, building another list.

Will update again once I have it apart and possibly create another thread for the head build/engine assembly

 

[Geotrash]

So quick update; LS364/425 is ready for next week 8K Cdn delivered to my doorstep. Would still need to swap the cam and springs to match so add another G, and then $750 for a dyno tune but that's happening regardless. Might still go that way in the end but not now. Truck still drivable and has good power and pressure most of the time but it gets "stuck" and will only rumble along at like 80kph with no power and then not restart, like the timing is fully advanced(or retarded). So I've made the choice to just do a top end tear down, get the heads off and cam out, inspect the bearings. Bearings bad, pull the block for rebuild/swap, bearings good then new cam, VVT delete and new/rebuilt heads. Top end could use a refresh anyways and I believe the block to be solid for another 100k or so. I've gone ahead and ordered a pile of parts, like 5k worth, so I'm committed now. Used Geotrashs cam swap thread for a guideline, so props to him, it really helped me get my mind around things. Here's the list;

From Summit;
ARP 134-1202 - ARP Chromoly Header Bolt Kits
ARP 134-3610 - ARP Pro Series Cylinder Head Bolt Kits
ARP 234-2503 - ARP Balancer Bolts
Flotek LS3-500 - FLOTEK 276cc LS3 Cylinder Heads
Summit Racing SUM-8720-1 - Summit Racing™ Pro LS Camshaft & Spring
Summit Racing SUM-V8010-8 - Summit Racing™ Race Valves for Chevrolet
Trick Flow Specialties TFS-30678505 - Trick Flow® VVT Delete Combos

Michigan Motorsports (Ebay store)
5/16 7.400 Chromoly Pushrods
LS3 Rocker Arms with upgraded Trunion Kit Installed
Delphi LS7 Lifters and Guide Trays

Rock Auto
FEL-PRO 26192PT Cylinder Head Gasket
GM GENUINE 12569427 Intake Valve
GM GENUINE 12589016 Camshaft Gasket
GM GENUINE 12600936 Rocker Arm Shaft Support
GM GENUINE 12639759 Air Deflector

Amazon
MAHLE Original MS16124 Exhaust Manifold Gasket
ACDelco 252-901 Professional Water Pump
GM LS Harmonic Balancer Install Tool Pulley
Valve Spring Compressor Tool Compatible with GM
Lucas Oil 10153 Assembly Lube

Have a few more little parts and speciality tools to order, building another list.

Will update again once I have it apart and possibly create another thread for the head build/engine assembly

Solid plan. Thanks for following up with your progress.

 

[Foggy]

You will probably end up needed a little diff length pushrods... but you'll have to assemble
it all first, then do the procedure to get your zero lash... So don't throw away your
receipt on those push rods, or wait til it's together then order what you need.
You will def need a good bit of tuning with that cam just to get it start up...
it WILL be choppy with the 112* lobe sep and 218/227 duration

 

[Foggy]

I was looking at the specs of your summit kit...
That's seems like a weird valve spring to use: 600 max lift when your
cam IS 600 lift... I know it's a kit so there must be some variance, but I'd double check
with summit that those springs will work

 

[CTUBS8732]

Sorry. Wrong post.

 

[kruznlow69]

So quick update; LS364/425 is ready for next week 8K Cdn delivered to my doorstep. Would still need to swap the cam and springs to match so add another G, and then $750 for a dyno tune but that's happening regardless. Might still go that way in the end but not now. Truck still drivable and has good power and pressure most of the time but it gets "stuck" and will only rumble along at like 80kph with no power and then not restart, like the timing is fully advanced(or retarded). So I've made the choice to just do a top end tear down, get the heads off and cam out, inspect the bearings. Bearings bad, pull the block for rebuild/swap, bearings good then new cam, VVT delete and new/rebuilt heads. Top end could use a refresh anyways and I believe the block to be solid for another 100k or so. I've gone ahead and ordered a pile of parts, like 5k worth, so I'm committed now. Used Geotrashs cam swap thread for a guideline, so props to him, it really helped me get my mind around things. Here's the list;

From Summit;
ARP 134-1202 - ARP Chromoly Header Bolt Kits
ARP 134-3610 - ARP Pro Series Cylinder Head Bolt Kits
ARP 234-2503 - ARP Balancer Bolts
Flotek LS3-500 - FLOTEK 276cc LS3 Cylinder Heads
Summit Racing SUM-8720-1 - Summit Racing™ Pro LS Camshaft & Spring
Summit Racing SUM-V8010-8 - Summit Racing™ Race Valves for Chevrolet
Trick Flow Specialties TFS-30678505 - Trick Flow® VVT Delete Combos

Michigan Motorsports (Ebay store)
5/16 7.400 Chromoly Pushrods
LS3 Rocker Arms with upgraded Trunion Kit Installed
Delphi LS7 Lifters and Guide Trays

Rock Auto
FEL-PRO 26192PT Cylinder Head Gasket
GM GENUINE 12569427 Intake Valve
GM GENUINE 12589016 Camshaft Gasket
GM GENUINE 12600936 Rocker Arm Shaft Support
GM GENUINE 12639759 Air Deflector

Amazon
MAHLE Original MS16124 Exhaust Manifold Gasket
ACDelco 252-901 Professional Water Pump
GM LS Harmonic Balancer Install Tool Pulley
Valve Spring Compressor Tool Compatible with GM
Lucas Oil 10153 Assembly Lube

Have a few more little parts and speciality tools to order, building another list.

Will update again once I have it apart and possibly create another thread for the head build/engine assembly

Any updates???

VERY similar situation. Rebuilt L92. Forged pistons, .005 power hone, OE cam. All good internals and so on. P0011 code at startup and stabilitrack codes. Ran for a month with same code, then started stalling out at stop lights. Live scanning data showed oil pressure drop to 6psi driving around a corner to a stop then killed. No restart till cold then same over and over. Can start and idlie till hot and idle for hours, once driving, will reset code then die at low rpm.

Pulled oil pan and timing cover. All new VVT parts, pickup o-ring, high pressure/volume melling oil pump, oil and filter. Cold start 65PSI, power brake almost 80 psi. Have not plugged oil pan pressure relieve valve.

Motor has all new forged pistons, new bearings, etc, OE cam. Minor scoring on cylinder walls which is why we did the power hone to 4.070. Since rebuild AND before We have lots of lifter/valve train noise cold, once warm, nice and quiet. New lifters, rockers with trunion upgrades and pushrods on rebuild.

Just parked it again to do some homework. Didn't see any issues with cam bearings when pan was down but didn't closely inspect. Odd thing in, once cold, will be 60PSI idle again. If walking cam bearings crank counterweights would contact right and be serious issue? Not just go away with cool down.


Also, mechanical Snap On gauge tapped into block plug on front driver side right behind oil pump verified pressures with gauges down to 20psi. Once below 20 psi, dash was about 5-10 below mech gauge but oil flow diagram shows many splits right at the oil valley below OE sender location.

 

[Geotrash]

Any updates???

VERY similar situation. Rebuilt L92. Forged pistons, .005 power hone, OE cam. All good internals and so on. P0011 code at startup and stabilitrack codes. Ran for a month with same code, then started stalling out at stop lights. Live scanning data showed oil pressure drop to 6psi driving around a corner to a stop then killed. No restart till cold then same over and over. Can start and idlie till hot and idle for hours, once driving, will reset code then die at low rpm.

Pulled oil pan and timing cover. All new VVT parts, pickup o-ring, high pressure/volume melling oil pump, oil and filter. Cold start 65PSI, power brake almost 80 psi. Have not plugged oil pan pressure relieve valve.

Motor has all new forged pistons, new bearings, etc, OE cam. Minor scoring on cylinder walls which is why we did the power hone to 4.070. Since rebuild AND before We have lots of lifter/valve train noise cold, once warm, nice and quiet. New lifters, rockers with trunion upgrades and pushrods on rebuild.

Just parked it again to do some homework. Didn't see any issues with cam bearings when pan was down but didn't closely inspect. Odd thing in, once cold, will be 60PSI idle again. If walking cam bearings crank counterweights would contact right and be serious issue? Not just go away with cool down.


Also, mechanical Snap On gauge tapped into block plug on front driver side right behind oil pump verified pressures with gauges down to 20psi. Once below 20 psi, dash was about 5-10 below mech gauge but oil flow diagram shows many splits right at the oil valley below OE sender location.

There are a few things that can cause oil pressure bleed-off on the L92 besides cam bearings:

1/ The L92 block is cast with the AFM towers in place, but they're sealed by o-rings on the bottom side of the valley pan. Did you replace the valley pan and/or the o-rings when you did the rebuild? If not, this would be my prime suspect in your case.

2/ The valve in the oil pan is a pop-off valve so if it's open, you'll have almost no pressure so I don't suspect that.

3/ There is a dog bone in the oil galley on the rear of the engine inside the bell housing. The o-rings on it can get hard over time and bleed off pressure when the oil thins out.

Also, if the cam bearing clearance is opening up, it doesn't mean that the cam will walk. It only means that the bearing clearances open up to the point that when the oil is hot it has a hard time maintaining pressure.

A short-term fix until you can get it apart to investigate would likely be Lucas oil stabilizer.

 

[kruznlow69]

There are a few things that can cause oil pressure bleed-off on the L92 besides cam bearings:

1/ The L92 block is cast with the AFM towers in place, but they're sealed by o-rings on the bottom side of the valley pan. Did you replace the valley pan and/or the o-rings when you did the rebuild? If not, this would be my prime suspect in your case.

2/ The valve in the oil pan is a pop-off valve so if it's open, you'll have almost no pressure so I don't suspect that.

3/ There is a dog bone in the oil galley on the rear of the engine inside the bell housing. The o-rings on it can get hard over time and bleed off pressure when the oil thins out.

Also, if the cam bearing clearance is opening up, it doesn't mean that the cam will walk. It only means that the bearing clearances open up to the point that when the oil is hot it has a hard time maintaining pressure.

A short-term fix until you can get it apart to investigate would likely be Lucas oil stabilizer.

New valley o-rings, very specific to order btw.

Brand new AC Delco oil pan which included that valve.

Felpro gasket kit included a new barbell which was installed.


Spoke to a could LS builders today, sounds like cam retainer plate can get worn and cause issues, even if only .001" out of spec. Always plug the relief valve, and triple check the barbell on place. Lastly check the cam bearings as much as possible with oil pan off.


SOOOO, we are going to pull motor back out.


Pass motor mount is shot, already did the H2 driver side upgrade but had a clunk and Revere power brake shows bad mount.

Only way to replace barbell if needed minus pulling trans, transfer case.

Easier to pull oil pan.

Easier to pull cam while out to inspect bearings, found a cheat with 5/16 solid rod to keep lifters in place.

Gotta pull exhaust manifolds, were just out so easy pull for mount.

Still same fluids dropped/wasted.

Annnnnnd just no more chances, especially with all new VVT parts already installed to no avail.

Gotta be a bigger internal bleeding problem, oil is leaking out and pump isn't starved. Dropping almost 50# of oil pressure once hot is insane.

Anyone else have any info??? Everything has been replaced minus the cam retainer plate.

 

[j91z28d1]

that front plate shouldn't be reused, it's cheap and if it leaks will kill oil pressure. I don't think there's anyways to see cam bearings with the cam in the block still.

if you're willing to pull the cam and inspect it's worth it. but I don't believe you can change them in the truck. they all look bad thou. Google ls cam bearing and welcome to the rabbit hole lol.

yours seems excessive. did you measure the bearings, main and rod yourself? cause that is a big drop.

 

[Geotrash]

New valley o-rings, very specific to order btw.

Brand new AC Delco oil pan which included that valve.

Felpro gasket kit included a new barbell which was installed.


Spoke to a could LS builders today, sounds like cam retainer plate can get worn and cause issues, even if only .001" out of spec. Always plug the relief valve, and triple check the barbell on place. Lastly check the cam bearings as much as possible with oil pan off.


SOOOO, we are going to pull motor back out.


Pass motor mount is shot, already did the H2 driver side upgrade but had a clunk and Revere power brake shows bad mount.

Only way to replace barbell if needed minus pulling trans, transfer case.

Easier to pull oil pan.

Easier to pull cam while out to inspect bearings, found a cheat with 5/16 solid rod to keep lifters in place.

Gotta pull exhaust manifolds, were just out so easy pull for mount.

Still same fluids dropped/wasted.

Annnnnnd just no more chances, especially with all new VVT parts already installed to no avail.

Gotta be a bigger internal bleeding problem, oil is leaking out and pump isn't starved. Dropping almost 50# of oil pressure once hot is insane.

Anyone else have any info??? Everything has been replaced minus the cam retainer plate.

Well that sucks. Sorry you have to pull it again.

While you have it out, I would plug those towers. Lingenfelter makes a kit for it that uses large rivets, or you can get a tap-in set from AMS Racing. I think Texas Speed sells a set as well. I've read of people still having oil pressure problems after replacing the o-rings, but having them still turn out to be the root cause.

Also, the 5/16" wooden dowel trick works great for holding the lifters in place. I cut mine to 24", which was perfect.

 

[Geotrash]

if you're willing to pull the cam and inspect it's worth it. but I don't believe you can change them in the truck.

You can change 4 of the 5, and the 5th one is almost never the problem, apparently. But you do have to pull the fans, radiator and transmission cooler out to get in there with the cam bearing puller. Of course, if you're pulling the cam, they're gonna be out already anyway. Gotta pull the oil pan too.

100% agree with you on that cam plate. Forgot about that one. That seal is a big source of oil pressure bleed-off.

 

[swathdiver]

high pressure/volume melling oil pump,

Which oil pump?

 

[kruznlow69]

Which oil pump?

We used a Melling 10355HV with standard spring.

 

[kruznlow69]

Update. We pulled motor yesterday. Found a couple things but sadly, all for nothing.

Backing up. When we pulled pan and timing cover last weekend, we swapped in
New Melling 10355HV High Volume/Pressure oil pump.
New GM VVT sprocket
New Melling solonoid valve
New GM Timing cover magnet
New pickup o-ring
Another reseal

Started up, hit almost 80PSI cold, then dwindles down to 5psi at operating temp, will drive but soon sets P0011 code and stabilitrack and will die and not restart.

Again, new engine built last year, installed a few months ago, less than 2000 miles. Was honed to 4.070, new DSS forged Pistons/moly rings, all new rockers, pushrods, lifters, trays. Polished cam, new cam bearings installed by engine machinist.

We found wrong valley cover gasket, but worked, and cam thrust plate had weird indents in the gasket. New gaskets again, new cam plate, pulled all rod caps and a couple main bearings to inspect, all are good. New barbell and rear cover gasket.

Cam bearings didn't appear to walk and upper 3nd looked good so we didn't pull it after finding the wrong valley gasket and maybe damaged cam plate gasket. We plugged the oil pan relief valve also.

We are losing our minds. 75psi swing in oil pressure... Gotta be bleeding out internally but can't see anything. Can the VVT be bad and dump oil electronically once warm?

 

[donjetman]

Put "plugs" in the AFM towers.

 

[j91z28d1]

I had to read back thru the thread. there's like 3 guys with the same issues?

wow that's weird.

so did any of the other guys fix there's? and one added Lucas Oil stabilizer and it made the whole truck run badly?


I'm so confused haha

 

[swathdiver]

One of the commonalities I see is that they are all using the 10355 pump (this and other threads across the internet) instead of the M365. It should not matter but it seems to.

What about that pressure relief valve in the pan? Anyone replace that with a plug and still have pressure issues?

 

[j91z28d1]

I had to Google those numbers. both are standard volume? just high pressure vs standard pressure.

huh. one of those web series on oiling did mention vvt take more oil volume than afm. I don't know that matters here as it seems some have non vvt cams and none have afm