Oil pressure 101
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Teching In
Joined: Dec 2010
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From: Northern New Mexico, Rocky Mountain High...7000 feet to be exact and we're in the valley!
Oil pressure 101 Noob to the board but been spinnin' wrenches for a couple of decades. Swapped motor out of 2002 'vette into 99 Z/28. Required oil pan swap and windage tray modification to use pickup tube/oil pan from Camaro in 'vette motor. Ran great for a couple of weeks but suddenly dropped oil pressure.
No rod knock but definite valve train noise, motor is from internet supplier in Florida supposedly low mile. Internally looked clean and fresh. After grazing the forum for a few hours tonight I see a few oil pressure threads and some talk of oil pump/bypass valve failure. I am unfamiliar with this particular engine platform from a hands on experience standpoint and welcome any suggestions before I begin the obligtory snoop and poop deduction of possibilities. Thanks in advance.
No rod knock but definite valve train noise, motor is from internet supplier in Florida supposedly low mile. Internally looked clean and fresh. After grazing the forum for a few hours tonight I see a few oil pressure threads and some talk of oil pump/bypass valve failure. I am unfamiliar with this particular engine platform from a hands on experience standpoint and welcome any suggestions before I begin the obligtory snoop and poop deduction of possibilities. Thanks in advance.
LSx engines make valvetrain noise because of the fairly aggressive cam lobes so that may be normal. Oil pressure should be constant with no fluctuations when running, mine(new 2004 LS6) runs 60 psi @ cold start, 45 psi @ hot 800 rpm idle, and will max out @ 65-70 psi 6500 rpm. Rule of thumb +10 psi for every 1000 rpm is the minimum.
Welcome to LS1 tech!
Welcome to LS1 tech!
Thread Starter
Teching In
Joined: Dec 2010
Posts: 10
Likes: 0
From: Northern New Mexico, Rocky Mountain High...7000 feet to be exact and we're in the valley!
LSx engines make valvetrain noise because of the fairly aggressive cam lobes so that may be normal. Oil pressure should be constant with no fluctuations when running, mine(new 2004 LS6) runs 60 psi @ cold start, 45 psi @ hot 800 rpm idle, and will max out @ 65-70 psi 6500 rpm. Rule of thumb +10 psi for every 1000 rpm is the minimum.
Welcome to LS1 tech!
Welcome to LS1 tech!
Thread Starter
Teching In
Joined: Dec 2010
Posts: 10
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From: Northern New Mexico, Rocky Mountain High...7000 feet to be exact and we're in the valley!
Here's where we're at now, dropped the pan and after looking at lubrication flow chart we blew compressed air into the pressure port (rearmost) on the block and the pressure bleeds into the forward port. Not srtaight through but there's definitely some leakage in what I'm assuming is a by pass valve. Not sure how big an issue this is, primarily wanted to look at bearings to see if there was damage. Thank God they look fine. Oil was darker than I'd like with some metallic residue. Where is the most likely early oil starvation failure bound to occur? Thanks
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Thread Starter
Teching In
Joined: Dec 2010
Posts: 10
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From: Northern New Mexico, Rocky Mountain High...7000 feet to be exact and we're in the valley!
Thanks I'm thinking of throwing this in for insurance. I've been roddin old school motors for a long time but we're going to set up a carbureted version for some mud racing so the learning curve is on.
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Verdad Gallardo We transfered the pickup tube from the Camaro engine along with the oil pan and windage tray (slight modification necessary) over to the 'vette engine. We reused the o-ring (stupidly) and I'm currently looking for a source for the "puffy" green one described by others on oil pressure issue related threads.
Here's where we're at now, dropped the pan and after looking at lubrication flow chart we blew compressed air into the pressure port (rearmost) on the block and the pressure bleeds into the forward port. Not srtaight through but there's definitely some leakage in what I'm assuming is a by pass valve. Not sure how big an issue this is, primarily wanted to look at bearings to see if there was damage. Thank God they look fine. Oil was darker than I'd like with some metallic residue. Where is the most likely early oil starvation failure bound to occur? Thanks
Here's where we're at now, dropped the pan and after looking at lubrication flow chart we blew compressed air into the pressure port (rearmost) on the block and the pressure bleeds into the forward port. Not srtaight through but there's definitely some leakage in what I'm assuming is a by pass valve. Not sure how big an issue this is, primarily wanted to look at bearings to see if there was damage. Thank God they look fine. Oil was darker than I'd like with some metallic residue. Where is the most likely early oil starvation failure bound to occur? Thanks
Why do they make different o-rings for the pick up? I have seen the green and the blue. What application would require a different o-ring? Or did they just update the o-ring to seal better?
Thread Starter
Teching In
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From: Northern New Mexico, Rocky Mountain High...7000 feet to be exact and we're in the valley!
[QUOTE=SOMbitch;14294167]Get a GM o-ring on there CORRECTLY and let us know how things are....[/QUOTE
Ordered it (small town) first thing this morning, I should have paid closer attention when my helper swapped the parts over. Especially in that area!
Experience is a hell of a teacher.
Ordered it (small town) first thing this morning, I should have paid closer attention when my helper swapped the parts over. Especially in that area!
Experience is a hell of a teacher.
Sounds like you may have piched the o-ring when you installed the pickup tube in the oil pump, specially if you reused your old one (Loses its shape)
. When you get your new o-ring lube the **** out of it so this doesnt happen, be very careful as you will be able to see the pickup sit flush on the pump. Don't overtighten that bolt either, it strips easy.
. When you get your new o-ring lube the **** out of it so this doesnt happen, be very careful as you will be able to see the pickup sit flush on the pump. Don't overtighten that bolt either, it strips easy. 
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
The Melling 10296 is a high pressure/high volume unit BTW. Be careful as the high volume units can suck the pan dry during sustained high rpm runs.Car is one app, truck is the other. The pick-up tubes are different sizes, thats the reason for the different thickness of o rings.
