High oil pressure? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SEVENTY1 · 03-13-2008, 06:40 PM

I had a rebuilt engine dropped in during the weekend, and my oil pressure seems really high. When it is at in park or neutral the needle almost goes all the way to the highest pressure. when in Drive or reverse it goes down to about 3/4 of the way, but when I step on the gas it seems to want to go almost all the way to the highest point. Is there any pointers or suggestions on what could be wrong. I know my father in law was having problems remembering what vacuum lines went where to the carburetor, could this be causing the problem, the maybe there are plugged in wrong?

Thanks

cruiserman · 03-13-2008, 07:34 PM

Plumb in another gauge before you do anything.

SEVENTY1 · 03-13-2008, 07:51 PM

Do you mean to replace the gauge with a new one?

*Billla* · 03-13-2008, 07:51 PM

Definitely check with a real gauge before getting too worried.

Did the rebuilt have a high volume/high pressure pump installed?

**SactoJim** · 03-13-2008, 08:00 PM

I wouldn't sweat it. Each mark on the oil pressure gauge is 15 lbs.....so last mark is 60 lbs. Pressure will come down a little as the oil viscosity (motor heats up) changes and also as you put more miles on the motor and it "loosens" up a bit.

Someone correct me if I'm wrong, but most factory oil pressure gauges are 60 lb, but I think 80 lb gauges were found in HD trucks.....it's usually indicated on the gauge face (the part you can't see with gauges in bezel).

ETsC10 · 03-13-2008, 08:04 PM

My 327 is a little over a year old and has a stock oil pump. It still pegs the guage when cold. I just don't drive it until it has a chance to warm up. Warmed up it runs about 3/4 guage. I don't think anything's wrong...just a nice tight engine.

SEVENTY1 · 03-13-2008, 08:30 PM

It has a stock oil pump. I have noticed that the pressure does lowers a little after engine warms up. I have only put about 75 miles on the motor since rebuild. I'm going to check out the gauge.

Thanks for all the input!

**El Jay** · 03-13-2008, 10:08 PM

I wouldn't worry about it.
MY '72 pegs the gauge @ "H" when it is first fired, then it drops down to 3/4 after things are warmed up. And that's w/ the original engine.

As an aside, I had a flat bottom with a BBC in it. When my son & I rebuilt the engine, we installed a high volume oil pump (Melling, I think). When cold, it would over range the pressure gauge so we pulled the sending unit & put in a "tee" & then ran the sending unit & a mechanical gauge off the "tee".
After that engine was warmed up, it would still have 50+# of oil pressure @ idle.
Never had a problem.

71 super · 03-14-2008, 07:21 AM

My BB Idles with 45 lbs of pressure hot or cold, running down the road the guage nearly pegs, and this is high for a bb, some sblocks in the past ran at or near the 60 lb mark all the time, would get worried if they dropped off from that. Lose a few motors to bad bearings and you will become a oil pressure watcher. If it goes up when off the gas and down when in the gas you have problems, would not worry about your situation, in fact I would be happy.

crazy longhorn · 03-14-2008, 08:53 AM

The bypass on the pump on my 383 is set @ 72 psi , hot @ 3000 rpms.....a little more than it needs, but not a problem. If you have a hy vol/hy press pump, you need to let it warm up before you "buzz" the throttle, & you should be fine. You might try a good aftermarket mechanical guage on it , just to check where you are. Figure about 10psi per 1000 rpms that you intend to run. crazyL

03-13-2008, 06:40 PM	#1
SEVENTY1 Registered User Join Date: Mar 2007 Location: Houston TX Posts: 50	High oil pressure? I had a rebuilt engine dropped in during the weekend, and my oil pressure seems really high. When it is at in park or neutral the needle almost goes all the way to the highest pressure. when in Drive or reverse it goes down to about 3/4 of the way, but when I step on the gas it seems to want to go almost all the way to the highest point. Is there any pointers or suggestions on what could be wrong. I know my father in law was having problems remembering what vacuum lines went where to the carburetor, could this be causing the problem, the maybe there are plugged in wrong? Thanks

03-13-2008, 07:34 PM	#2
cruiserman Registered User Join Date: Dec 2006 Location: Idaho Posts: 210	Re: High oil pressure? Plumb in another gauge before you do anything. __________________ 72 C2500 LWB 402 Sierra Grande 05 Odyssey 08 Tundra

03-13-2008, 07:51 PM	#3
SEVENTY1 Registered User Join Date: Mar 2007 Location: Houston TX Posts: 50	Re: High oil pressure? Do you mean to replace the gauge with a new one?

03-13-2008, 07:51 PM	#4
Billla Account Suspended Join Date: Sep 2005 Location: Monroe, WA Posts: 3,815	Re: High oil pressure? Definitely check with a real gauge before getting too worried. Did the rebuilt have a high volume/high pressure pump installed?

03-13-2008, 08:00 PM	#5
SactoJim Registered User Join Date: Oct 2005 Location: Sacramento, CA Posts: 1,970	Re: High oil pressure? I wouldn't sweat it. Each mark on the oil pressure gauge is 15 lbs.....so last mark is 60 lbs. Pressure will come down a little as the oil viscosity (motor heats up) changes and also as you put more miles on the motor and it "loosens" up a bit. Someone correct me if I'm wrong, but most factory oil pressure gauges are 60 lb, but I think 80 lb gauges were found in HD trucks.....it's usually indicated on the gauge face (the part you can't see with gauges in bezel). __________________ 72 Cheyenne SWB Fleet Nut & bolt frame off in progress...99.9999% - supercharged 383 - 4 wheel discs - relocated fuel tank - My Build Thread

03-13-2008, 08:04 PM	#6
ETsC10 Hand Crafted C-10 Join Date: Aug 2006 Location: Burien, WA Posts: 5,180	Re: High oil pressure? My 327 is a little over a year old and has a stock oil pump. It still pegs the guage when cold. I just don't drive it until it has a chance to warm up. Warmed up it runs about 3/4 guage. I don't think anything's wrong...just a nice tight engine.

03-13-2008, 08:30 PM	#7
SEVENTY1 Registered User Join Date: Mar 2007 Location: Houston TX Posts: 50	Re: High oil pressure? It has a stock oil pump. I have noticed that the pressure does lowers a little after engine warms up. I have only put about 75 miles on the motor since rebuild. I'm going to check out the gauge. Thanks for all the input! Last edited by SEVENTY1; 03-13-2008 at 08:30 PM.

03-13-2008, 10:08 PM	#8
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: High oil pressure? I wouldn't worry about it. MY '72 pegs the gauge @ "H" when it is first fired, then it drops down to 3/4 after things are warmed up. And that's w/ the original engine. As an aside, I had a flat bottom with a BBC in it. When my son & I rebuilt the engine, we installed a high volume oil pump (Melling, I think). When cold, it would over range the pressure gauge so we pulled the sending unit & put in a "tee" & then ran the sending unit & a mechanical gauge off the "tee". After that engine was warmed up, it would still have 50+# of oil pressure @ idle. Never had a problem. __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

03-14-2008, 07:21 AM	#9
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,079	Re: High oil pressure? My BB Idles with 45 lbs of pressure hot or cold, running down the road the guage nearly pegs, and this is high for a bb, some sblocks in the past ran at or near the 60 lb mark all the time, would get worried if they dropped off from that. Lose a few motors to bad bearings and you will become a oil pressure watcher. If it goes up when off the gas and down when in the gas you have problems, would not worry about your situation, in fact I would be happy.

03-14-2008, 08:53 AM	#10
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Re: High oil pressure? The bypass on the pump on my 383 is set @ 72 psi , hot @ 3000 rpms.....a little more than it needs, but not a problem. If you have a hy vol/hy press pump, you need to let it warm up before you "buzz" the throttle, & you should be fine. You might try a good aftermarket mechanical guage on it , just to check where you are. Figure about 10psi per 1000 rpms that you intend to run. crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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