Low Oil Pressure
Thread Starter
Racer
Joined: Jul 2002
Posts: 378
Likes: 0
Low Oil Pressure
I bought a new forged shortblock from a vendor and had a local shop assemble the longblock. They've installed it, but there is an oil pressure problem. The cold oil pressure is about 35 psi, but after it warms up the pressure creeps down to less than 10 psi. Once it gets below 10 we kill the engine to prevent any damage. I know GM says 8 psi is okay for 800 rpms, but I'm not happy with that at all. Here's what we've checked/replaced so far:
1.) Replaced oil pressure sensor to eliminate it as an issue.
2.) Checked O-Ring (it was fine) and replaced it
3.) Replaced stock LS6 oil pump with a new ported/shimmed LS6 pump to elimate it as a potential issue.
4.) Checked galley plug depth in back and it is in the correct position (not blocking flow).
5.) Checked plug in front of engine (it's there and not leaking).
6.) Oil pump spacers for double roller chain were on correctly (asymetric)
7.) Oil weight was changed from 10w-30 to 20w-50 with no appreciable difference.
Does anyone have an idea of what could be wrong? What else could we check? I'm not sure what the main clearances are, but I doubt they are that loose.
1.) Replaced oil pressure sensor to eliminate it as an issue.
2.) Checked O-Ring (it was fine) and replaced it
3.) Replaced stock LS6 oil pump with a new ported/shimmed LS6 pump to elimate it as a potential issue.
4.) Checked galley plug depth in back and it is in the correct position (not blocking flow).
5.) Checked plug in front of engine (it's there and not leaking).
6.) Oil pump spacers for double roller chain were on correctly (asymetric)
7.) Oil weight was changed from 10w-30 to 20w-50 with no appreciable difference.
Does anyone have an idea of what could be wrong? What else could we check? I'm not sure what the main clearances are, but I doubt they are that loose.
Safety Car
Joined: May 2004
Posts: 4,811
Likes: 2
From: Simpsonville SC
Im having the same problem with my stock LS1. It hasnt dropedbelow 10 psi but came pretty close. I took it to the dealer and they said and some Forum members said its probley the heat. But I dont like it either. So if your motor is similiar to mine I would like to know how to fix it, I guess start over with a built motor 
. Well good luck and I hope someone can help both of us out 
. Well good luck and I hope someone can help both of us out
Instructor
Joined: Sep 2001
Posts: 119
Likes: 0
From: Evansville IN
I had a problem with low oil pressure at high rpm and at idle. I ended up running straight 50 weight oil. (SAE 50) I then changed to a well known oil filter such as mobil 1 (m1-107), ac delco (upf 44), K&N ect. After changing the oil and filter my oil pressure problem has since dissappered.
It does seem like in your case that your bearing clearances could be causing the problem.
It does seem like in your case that your bearing clearances could be causing the problem.
Last edited by mkern1; Sep 18, 2005 at 06:01 PM.
Burning Brakes
Joined: Sep 2001
Posts: 1,173
Likes: 1
From: Aguila AZ
Is this a solid roller motor? Comp cams had a problem with solid lifters that caused low oil pressure in one of my engines. They are replacing a set of lifters that caused this problem.
Shirl
SD Racing Enterprises
Shirl
SD Racing Enterprises
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Originally Posted by Torched Z
This motor has the stock hydraulic lifters. If it was bearing clearances would we be hearing any noises?
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Uber Waxer
Joined: May 2004
Posts: 8,651
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From: Hanover MD
Cruise-In 8-9-10-11 Veteran
CI 9, 10 & 11 Car Show Winner
St. Jude Donor '08-'10
I had an ARE 347 and it had low oil pressure because of larger clearence.
i had the motor for 2 years, made a bunch of nitrous passes and the guy i sold it to is still running it with no problems.
i would just keep an eye on it, 10 at idle is fine and mine would run about 50 at wide open.
i had the motor for 2 years, made a bunch of nitrous passes and the guy i sold it to is still running it with no problems.
i would just keep an eye on it, 10 at idle is fine and mine would run about 50 at wide open.