Normal oil pressure?

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Old Sep 19, 2018 | 12:16 PM
  #1  
72455's Avatar
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1972 U code Supreme
 
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From: Chesapeake, VA
Normal oil pressure?

Hey all I was just wondering what normal oil pressure should be for my 72 Cutlass Supreme. It has the U code 455 with some work done. Sitting at idle it's around 25 psi and driving it's around 48-50.
Am I good?
Old Sep 19, 2018 | 12:36 PM
  #2  
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The rule of thumb is 10psi per 1000 rpm minimum. I would not worry about that pressure.
Old Sep 19, 2018 | 12:42 PM
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What oil are you using? Those numbers seem perfectly healthy.
Old Sep 19, 2018 | 02:11 PM
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72455's Avatar
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1972 U code Supreme
 
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Originally Posted by bw1339
What oil are you using? Those numbers seem perfectly healthy.
I just did an oil change today.. Valvoline VR1 10W30
Old Sep 19, 2018 | 03:19 PM
  #5  
Allan R's Avatar
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I'm surprised you haven't done a compression test on your car yet. You've done darn near everything else.
Old Sep 19, 2018 | 05:32 PM
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That’s normal oil pressure for a stock Olds. When those numbers begin to change its time for some exploratory surgery, starting with the nylon camshaft gear. Most likely the nylon starts chipping off, and ends up in the oil pump pickup
Old Sep 19, 2018 | 06:55 PM
  #7  
72455's Avatar
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1972 U code Supreme
 
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Originally Posted by Allan R
I'm surprised you haven't done a compression test on your car yet. You've done darn near everything else.
Lol...I only fix what's broke Allan, and if I can get sideways from a roll, then I'm thinking I'm probably ok on the compression. Although I'll admit the thought has crossed my mind 😀
Old Sep 20, 2018 | 09:30 AM
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Originally Posted by 72455
if I can get sideways from a roll, then I'm thinking I'm probably ok on the compression.
FYI, back in the early 80s a friend of mine bought a farily trashed '71 SX convertible and it would get sideways even though it was running on 7 cylinders.
Old Sep 24, 2018 | 10:16 AM
  #9  
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My stock lower end 455 runs in that range, 20 PSI idle Hot to 40-45 at power.
Old Sep 24, 2018 | 05:43 PM
  #10  
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Originally Posted by oldcutlass
The rule of thumb is 10psi per 1000 rpm minimum. I would not worry about that pressure.
as for this rule..is there some sort of a minimum PSI? i mean if that applies correctly there would be 8 PSI at idle..wouldnt that be too low?
Old Sep 24, 2018 | 06:37 PM
  #11  
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I like to see a minimum of 20. My old tired 330 ran about 7.5 on a 90* day with 10w30 in it with no knocks or ticks. Its really about flow not pressure.
Old Sep 25, 2018 | 11:38 AM
  #12  
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Originally Posted by EightballZ
as for this rule..is there some sort of a minimum PSI? i mean if that applies correctly there would be 8 PSI at idle..wouldnt that be too low?

the minimum would be just enough to keep the light off!

i agree, I would like to see at least double digit idle oil pressure.
Old Oct 18, 2018 | 08:19 AM
  #13  
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If I may inject some humor here too:
Exploratory Surgery - my son works as a Cardiac sonographer (scanning hearts). He came home from work one day after open-heart-surgery, and said "Dad, I can do open-heart-surgery with the tools you have in your Shop" !
As mechanics troubleshooting our engine builds of all types, it does take lots of Exploratory Surgery.

And when Fun71 mentioned getting sideways on 7-cylinders, when I am doodling around in my WRX on my trips to the snow-ski park, I call it "Slideways" as I am headed for the snowbank. Doggon if I didn't burn-up a Vicious-Coupler (center-diff) in the transfer-case. For those of you who may not be on the know of Subaru drivetrains, the transfer case on these autos essentially has a Posi-unit (Viscious Coupler) which allows slippage between the front and rear differentials. If you enjoy spinning broadies, you will burn-up this Dealer-only part which is only a $870 jewel. The unit is a non-serviceable sealed unit. I think it is a POS and could be made better, but mine lasted 9-years.
I wish the Subaru's had a Diff-Lock like the full-sized American 4x4's, where you can lock front to rear in the transfer-case, and then Punch-It. changing times !

Talking Oil Pressure - I put Slick 50 in a 460 ford engine once only, and drained it back out because my oil pressure dropped significantly. ( Scary low )
Normal oil pressure was from 20 at idle to 60 buzzing the interstate w/ 4:10 gearing. If I remember right, after adding the Slick 50, it dropped to 5 psi at idle, so I never did run the engine on the road with that low of pressure, and immediately drained the oil.
Old Oct 18, 2018 | 01:47 PM
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For running 10w30, imo, those numbers are good. It used to be 5lbs oil pressure would keep an oil pressure light off. That's why they were called "idiot" lights. In the late 1960s I was dating a girl whose Father had a used car lot. Real bombs with "buy here, pay here.." Anyway, he would always be switching out her cars, sell them out from under her. She was driving a 1964 Rustang, opps, I mean Mustang. Yellow with a 260 v-8.
She stopped in, I was working on my Chevelle in the garage. I heard the clacking from the car. She said the oil light was on and would I look at it. I pulled the dipstick, nothing. One qt, nothing, 2 qts, nothing, 3qts, finally a little on the stick, damn near 4qts. I had her start the cars and the lifters started pumping up. A few minutes later, engine is smoothed out and quite. I couldn't believe the engine wasn't ruined. I showed her how to check the oil and told her how important oil is. She then said, "would you change my oil?" I said, I just did! I did get the proper oil filter and changed the filter and added a qt. The filter was the weight of a brick. He sold the car soon after, the next one was worse, can you say "brake lines!!" That's another story.
Old Oct 20, 2018 | 05:52 AM
  #15  
olds 307 and 403's Avatar
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Originally Posted by Kennybill
For running 10w30, imo, those numbers are good. It used to be 5lbs oil pressure would keep an oil pressure light off. That's why they were called "idiot" lights. In the late 1960s I was dating a girl whose Father had a used car lot. Real bombs with "buy here, pay here.." Anyway, he would always be switching out her cars, sell them out from under her. She was driving a 1964 Rustang, opps, I mean Mustang. Yellow with a 260 v-8.
She stopped in, I was working on my Chevelle in the garage. I heard the clacking from the car. She said the oil light was on and would I look at it. I pulled the dipstick, nothing. One qt, nothing, 2 qts, nothing, 3qts, finally a little on the stick, damn near 4qts. I had her start the cars and the lifters started pumping up. A few minutes later, engine is smoothed out and quite. I couldn't believe the engine wasn't ruined. I showed her how to check the oil and told her how important oil is. She then said, "would you change my oil?" I said, I just did! I did get the proper oil filter and changed the filter and added a qt. The filter was the weight of a brick. He sold the car soon after, the next one was worse, can you say "brake lines!!" That's another story.
Cool story. Here is one and another reason why I love the Olds V8. My friend's girlfriend had an Chevy Impala 4 door with an 307 Olds V8. You got love GM Canada, the Cutlass line in the 80's, like Pontiac's since the 60's, got the the chebby V8. The only exception was the Hurst/Olds, 442 and 88 Cutlass, basically being US cars like the bigger Caprice, Impala and Delta 88/98, also got the Olds V8. Anyways her brothers bagged the **** out of it for years. One long weekend we took this car to the resort an hours drive, Oak Lake Island resort in Manitoba, my Wife's Uncle owned it, stole hundreds of thousands of dollars from my In-laws cattle farm to dig the marina and build his fancy house on the lake shore. Yes, he is a horrible man, hopefully he leaves everything to my brother in law, never married or had children. He sold the resort for 2 million, my in-laws did receive money at the time of the sale as well, as they should have. Anyways, we drove the car to the floor there and back, 4 times that long weekend. The car leaked a bunch and burned oil as well. We added 3 to 4 liters(quarts) every time, 15W40 diesel oil. That car ran for years, until it back fired through the carb and caught fire, it must of had 400,000 km when it died. Same thing, it started clacking when it ran low on oil, otherwise sounded fine.
Old Oct 22, 2018 | 07:23 PM
  #16  
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From: Redding, California
Do young adults check oil today ? or do they wait until it is time to take the auto in for its scheduled oil-change, oh, well, no biggie if it is 6-months late right !

I was reading an article on "hotrodders.com", I think, but the title of the thread was "how to buy a junkyard engine". I liked the article because it said that most times the dirtiest engine is the one that has never been apart, and that might just be the "Keeper." I recently purchased a transmission for my old ****** jeep, and when I went to look at it the thing was caked in oily grime and 70-years accumulation of grime. Then I remembered the article, and purchased it. Once I got it all cleaned up, it was a Keeper.
Gotta love Oil.
Old May 6, 2026 | 06:53 PM
  #17  
Farnsee's Avatar
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Just an FYI for whoever comes across this ...

I realize this is a very old thread , but I found this in my 1970 Oldsmobile service manual that I took from the Chev-Olds Dealership I work at as a kid in 1973. My 1970 442 W30 had low oil pressure from the day I bought it in 1977. At first, it was a concern for me but once I found this in the service manual i pretty much didn't worry about it. 1970 Oldsmobile service manual page 6B4 normal oil pressure is 7 PSI in Neutral at Idle.35 PSI at 1500 to 3500 RPM . I run 15W40 in it these days . The Oil Gauge Needle hardly moves when at idle when warm...




Old May 6, 2026 | 07:30 PM
  #18  
oldcutlass's Avatar
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Originally Posted by Greaser007
Do young adults check oil today ? or do they wait until it is time to take the auto in for its scheduled oil-change, oh, well, no biggie if it is 6-months late right !

I was reading an article on "hotrodders.com", I think, but the title of the thread was "how to buy a junkyard engine". I liked the article because it said that most times the dirtiest engine is the one that has never been apart, and that might just be the "Keeper." I recently purchased a transmission for my old ****** jeep, and when I went to look at it the thing was caked in oily grime and 70-years accumulation of grime. Then I remembered the article, and purchased it. Once I got it all cleaned up, it was a Keeper.
Gotta love Oil.
My rule of thumb for buying used engines in the wrecking yard was to find one that was totaled in the front with no fan or crank pully damage because you knew it ran when it was wrecked.
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