Go Back   LS1TECH > LS1-LS2-LS3-LS6-LS7 PERFORMANCE > Advanced Engineering Tech
Sign in using an external account
Register Forgot Password?
Search

Advanced Engineering Tech
For the more hardcore LS1TECH residents
Sponsored by
Whipple Super Chargers

uber high oil pressure

Reply
 
Thread Tools Search this Thread
Old 03-10-2010, 07:53 PM   #1
Staging Lane
 
jfrc2000's Avatar
 
Trader Rating: 0
Join Date: Nov 2005
Location: Central Tx
Posts: 50
Default uber high oil pressure

i'll make this as short as possible. when this motor was built, it originally had almost no oil pressure. when the motor got hot, it was closer to 0. so i swapped in a melling oil pump, it helped some.
therefore i eventually pulled the motor, tore it down, and found the machine shop installed the cam bearings incorrectly. so new machine shop and new bearings. before reassembly, i DID recheck clearances, and it was good.
so re-rebuilt motor back in car, oil pressure at idle is 120-130 lbs! tired of working on it, i haven't driven it much.
so finally, swapped the stock ls6 ported pump this past weekend. well you guessed it, oil pressure is still 130 lbs. WTF?! is it a bad sending unit? before everybody says to check it with a mechanical guage, i would have if I knew anybody or had access to one.
i'm really tired of all this work and going in circles- there's plenty of other things i'd rather work on or spend money on. any ideas or suggestions would be great
jfrc2000 is offline   Reply With Quote
Old 03-10-2010, 11:03 PM   #2
Launching!
 
Trader Rating: 1
Join Date: May 2009
Location: easton, md
Posts: 227
Default

dude go pick up a cheap sunpro mechanical oil pressure gauge for 30 bux and use that to check it, you don't need an expensive one. i can't see the pressure actually being that high at idle, you would most likely rupture the filter or at least shoot past the seal.
livefast1 is offline   Reply With Quote
Old 03-11-2010, 08:44 AM   #3
Moderator
 
jimmyblue's Avatar
 
Trader Rating: 11
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,318
Default

I don't know where the pressure relief spring /ball is on
these motors, but there should be one. Maybe the oil pump
is a "high pressure / high volume" one, and "high" is too
high. Or maybe the relief path is simply messed up.
__________________


2002 SS convertible

SLP Blackwing lid, 85mm MAF, 85mm Professional Products intake & TB, SLP CME, JBAs/Mufflex tubes . SLP Y, McCord cutout, Fuddle 3500/2.0, GM truck pan, '98 flexplate, 3.42s, T-2R, MAC cover, welded tubes, Hotchkiss PHR, springs; BMR bolt-in LCA brackets, K-member; UMI TA, boxed stock 1LE LCAs, SLP Bilstein / Gabriel air shocks (F/R); Strano 35/22 sway bars, 224/224 116 cam, LT1 rad, HPTuners 12.6@112MPH
jimmyblue is offline   Reply With Quote
Old 03-11-2010, 09:26 AM   #4
TECH Fanatic
 
ryarbrough's Avatar
 
Trader Rating: 18
Join Date: Jan 2007
Location: Mechanicsville, VA
Posts: 1,194
Default

What are the clearences on the bearings. Some of the melling pumps are supposed to be used only with "race" engines with looser tolerences in the main/rod/cam bearing area.
__________________
99 Formula - Forged 347, MS4, PRC Stage 2.5 5.3L Heads, ZEX Perimeter Plate, TH400, Yank Eliminator 3600

10.08 @ 134 - 435 hp NA through the big auto

Richmond Performance Musclecars...The Real RPM!
ryarbrough is offline   Reply With Quote
Old 03-11-2010, 02:07 PM   #5
Staging Lane
 
jfrc2000's Avatar
 
Trader Rating: 0
Join Date: Nov 2005
Location: Central Tx
Posts: 50
Default

it has been awhile since i rebuilt engine, but with plastiguage it was right in the middle of the tolerances

whether it was the high volume melling, or the relief check inside, that is why i tore it apart to swap back to the stock ls6 pump- and it still is 130 lbs at idle

and the melling does flow @ 20% more, but both are supposedly producing the same pressure?!
jfrc2000 is offline   Reply With Quote
Old 03-11-2010, 02:16 PM   #6
TECH Fanatic
 
ryarbrough's Avatar
 
Trader Rating: 18
Join Date: Jan 2007
Location: Mechanicsville, VA
Posts: 1,194
Default

If it flows 20% more and the journal clearences are tight, that extra 20% has nowhere else to go, making pressure rise. If that is the case I'd be willing there's some crazy cavitation going on in the pump though. I'd check with a manual gauge first and see what that tells you. I'd be very surprised if that didn't hurt a seal somewhere if the pressure really is that high...
__________________
99 Formula - Forged 347, MS4, PRC Stage 2.5 5.3L Heads, ZEX Perimeter Plate, TH400, Yank Eliminator 3600

10.08 @ 134 - 435 hp NA through the big auto

Richmond Performance Musclecars...The Real RPM!
ryarbrough is offline   Reply With Quote
Old 03-11-2010, 04:36 PM   #7
Staging Lane
 
Trader Rating: 5
Join Date: Oct 2009
Location: Arkansas
Posts: 53
Default

I had the same problem on my gto and it was the sending unit. good luck
billy.johnson is offline   Reply With Quote
Old 03-12-2010, 01:00 PM   #8
FormerVendor
 
XtraCajunSS's Avatar
 
Trader Rating: 2
Join Date: Dec 2001
Location: Baton Rouge, LA, USA
Posts: 1,955
Default

You're not making 130psi at idle with an LS anything and a stock type pump. I've had the same issue on multiple cars and it always comes down to the sender. Double check your pressure with a mechanical guage and with a Melling you should see approx 60psi cold depending on clearances. FWIW, I've used Melling HV's on almost everything with no ill effects. In my experience, you really can't have too much oil pressure in an LS engine.

Shane
XtraCajunSS is offline   Reply With Quote
Old 03-14-2010, 02:43 PM   #9
Staging Lane
 
Trader Rating: 0
Join Date: Jan 2009
Location: King George, VA
Posts: 69
Default

Just got done reading the post and all the replies. I will be changing my sending unit just for good measure and installing a melling HV(p/n 10295) in my build.

And a 130 lbs of pressure??? you should have oil going all ove the place, if it really was that high. Good luck, I hope changing the sender unit works out.
__________________
02 Camaro Z28 T56 - 220/220 .581/.581 regrind cam, pacesetter LT, ORY, corsca catback, comp cam lifters, comp cam push rods, PAC springs, stainless steel polished lid, ported TB, !AIR, !rear 02s, ARP bolts everywhere, stock LS6 intake, SLP double chain, SLP H/O oil pump, new OEM type clutch, pressure plate, flywheel, slave clyinder, master clyinder(drill mod), HP Tuners & new GM gaskets everywhere
!All together but will not start!
Ryneman is offline   Reply With Quote
Old 03-14-2010, 03:43 PM   #10
TECH Addict
 
Trader Rating: 77
Join Date: May 2002
Location: louisville,ky
Posts: 2,111
Send a message via AIM to black98ws6ta
Default

Corvette? Bad sending unit.
__________________
Red 99 ws6 Trans Am:
Fastest Stock ls1 shortblock in a f-body.... only headstuds/cam/springs/pushrods 5.96 @ 118 and 9.30@ 147
Coming soon:
03 cobra with a couple turbo's, 4l80e, driven daily and 5 second time slips
LSx swapped foxbody:
5.06@142
black98ws6ta is offline   Reply With Quote
Old 03-15-2010, 02:26 AM   #11
TECH Resident
 
Trader Rating: 0
Join Date: Apr 2008
Location: Right here, right now!
Posts: 766
Default

That is a lot of posts you will need . LOL.

Quote:
Originally Posted by XtraCajunSS View Post

Shane
__________________

"Killing internet myths... one post at a time..."

2000 Pewter SS-M6 #2515
408 SR ET LS7 in the works...

2005 Redline CTS-V stock?!?!
12.97 @ 112.90 2.36 60'
I only have 1 spare rear end...

Shane@thunderracing.com
THUNDER RACING
Toll-Free 877-516-7223
Feel The Thunder!

rsz288 is offline   Reply With Quote
Old 03-17-2010, 01:12 PM   #12
TECH Fanatic
 
1 FMF's Avatar
 
Trader Rating: 1
Join Date: Mar 2002
Location: CT
Posts: 1,500
Default

what kind of oil pressure gauge do you have that's telling you over 100 psi?
The gauge in the dash only goes to 80, and i haven't seen any aftermarket gauges over 80psi not that i would remember if i did,
if you did have 120+ psi oil pressure I would think you would see evidence of that by the oil filter casing bulging outward some,
and the oil pressure relief valve is on the oil pump, the only way to get high pressure like you describe is for that relief valve to stick closed. And even at idle or low rpms the pump isn't spinning fast enough to build over 100 psi, if it did then there would have to be near zero oil flowing through the bearings, lifters and up the pushrods.
so yeah, check the sender first. the wire or sender is probably shorting to ground which is pegging the gauge. And the oil pressure relief valve on most of the LS1 pumps is set at 70 psi last i knew, so if that relief valve is working there is absolutely no way you can have an increase in oil pressure at your oil pressure sender (unless the laws of physics are different in your engine).
__________________
2002 SS
1 FMF is offline   Reply With Quote
Old 03-28-2010, 09:07 AM   #13
TECH Addict
 
elias_799's Avatar
 
Trader Rating: 8
Join Date: Oct 2008
Location: toronto ontario canada
Posts: 2,041
Default

i have a melling 296 high volume/hi pressure and the most i see is 75psi at cold idle with 15w40 oil
elias_799 is offline   Reply With Quote
Old 09-15-2012, 06:42 PM   #14
Teching In
 
Trader Rating: 0
Join Date: Sep 2011
Posts: 4
Default Resurrect this thread-crate motor high oil pressure

Hello,
I'm fairly new to this site and it may be the first time I've posted with an issue. I have an Ultima GTR (http://www.ultimasports.co.uk/Default.aspx) and it has a factory LS7 crate engine bolted to a Porsche 993 transmission. I purchased the car from it's builder/driver who ran it at Sebring and used it on the streets of Florida. It now has about 5K miles on it and it's a great car.
The problem is that the oil pressure reads wild high. The car has a RacePak digital (LCD) street panel for the instrument panel and presumably the matching RacePak senders and harness. Pressure at startup idle read 95lb's and when cold, and rev'ing of the engine (to 3000 for example) yields a pressure of over 100lbs. Once warmed up, at 70 mph at 2200 rpm it reads 94lbs and any time I put my foot in it it reads over 100lbs. The peak I've seen is about 109lbs.
When warm, it idles in the 55-65lb range.
Seems to me that this is way too high. The previous owner was concerned, called Chevy and was told that some early runs just run that high. He's a straight up guy and an excellent and perfectionist tech, so I doubt that he'd leave it that way for his use, and would not hand it off to me with some story.
So, I need help here. Should I install a mechanical gauge to check the pressure? Where does that get inserted and what gauge should I use? If it still reads high, what are my options. I really am concerned about a catastrophic failure so I drive it only gently - which is not what a great CanAm-styled sports car with a great engine was designed to do.
Thanks in advance,
V
Verde is offline   Reply With Quote
Old 09-15-2012, 08:57 PM   #15
TECH Resident
 
Trader Rating: 0
Join Date: Apr 2008
Location: Right here, right now!
Posts: 766
Default

Have seen these aftermarket dashes read incorrectly vs the factory sensors - and not just oil pressure. Also temp, rpm, speed. Unclear why.

Best to get an OBDII reader and take a look at what the factory sensor says.

Sure is a waste of power generating that oil pressure if it is for real. Either very high volume pump or tight clearances or both, if its not the calibration of the pil pressure readout.

Quote:
Originally Posted by Verde View Post
Hello,
I'm fairly new to this site and it may be the first time I've posted with an issue. I have an Ultima GTR (http://www.ultimasports.co.uk/Default.aspx) and it has a factory LS7 crate engine bolted to a Porsche 993 transmission. I purchased the car from it's builder/driver who ran it at Sebring and used it on the streets of Florida. It now has about 5K miles on it and it's a great car.
The problem is that the oil pressure reads wild high. The car has a RacePak digital (LCD) street panel for the instrument panel and presumably the matching RacePak senders and harness. Pressure at startup idle read 95lb's and when cold, and rev'ing of the engine (to 3000 for example) yields a pressure of over 100lbs. Once warmed up, at 70 mph at 2200 rpm it reads 94lbs and any time I put my foot in it it reads over 100lbs. The peak I've seen is about 109lbs.
When warm, it idles in the 55-65lb range.
Seems to me that this is way too high. The previous owner was concerned, called Chevy and was told that some early runs just run that high. He's a straight up guy and an excellent and perfectionist tech, so I doubt that he'd leave it that way for his use, and would not hand it off to me with some story.
So, I need help here. Should I install a mechanical gauge to check the pressure? Where does that get inserted and what gauge should I use? If it still reads high, what are my options. I really am concerned about a catastrophic failure so I drive it only gently - which is not what a great CanAm-styled sports car with a great engine was designed to do.
Thanks in advance,
V
rsz288 is offline   Reply With Quote
Old 09-16-2012, 05:55 PM   #16
Teching In
 
Trader Rating: 0
Join Date: Sep 2011
Posts: 4
Default

Thank you for the response.
Will the OBDII read any differently? Doesn't it rely on the same sensor? Does your hypothesis assume that the sensor is alright and it is the display that is incorrect? Just want to make sure I'm following you and that I'm testing for the right thing.
V

Quote:
Originally Posted by rsz288 View Post
Have seen these aftermarket dashes read incorrectly vs the factory sensors - and not just oil pressure. Also temp, rpm, speed. Unclear why.

Best to get an OBDII reader and take a look at what the factory sensor says.

Sure is a waste of power generating that oil pressure if it is for real. Either very high volume pump or tight clearances or both, if its not the calibration of the pil pressure readout.
Verde is offline   Reply With Quote
Old 09-16-2012, 09:48 PM   #17
TECH Fanatic
 
ZTwentyAteU's Avatar
 
Trader Rating: 12
Join Date: May 2005
Location: Nashville, TN
Posts: 1,253
Default

cheap oil pressure gauge from parts store. do it

60psi is fine. Ive seen 80 on cold starts plenty of times
__________________
2000 Z28 Drag Car--02 z28 m6 stripper--
ZTwentyAteU is offline   Reply With Quote
Old 09-16-2012, 09:48 PM
LS1Tech
Pontiac Firebird




Paid Advertisement
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Another oiling issue thread matt99 Generation III Internal Engine 8 07-12-2013 02:04 PM
LS1 Low oil pressure. Any more ideas to try before I buy new engine? sweet99ss Generation III Internal Engine 27 04-06-2013 09:04 PM
Low oil pressure smokeshow Generation IV Internal Engine 39 02-22-2012 02:45 PM
oil pressure switch on 2001 corvette need some info and help bigfatls6 Generation III External Engine 8 02-07-2012 08:51 AM
Need help : low oil pressure but no symptoms! Give me things to check akw408 Generation III Internal Engine 5 11-17-2002 08:37 PM


Tags
60, 98, bearing, camaro, da, engine, high, hurt, ls1, oil, pressure, spring, supposed, tired, uber, whats


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off



Join Ls1Tech

All times are GMT -5. The time now is 03:47 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Advertising - Terms of Service - Privacy Statement - Terms of Service - JOBS
Emails & Contact Details