Oil pressure question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Project1970 · 05-27-2003, 06:04 AM

I just realized I'd never paid attention to exactly where my oil pressure gauge sits, especially when hot...all I do is make sure it's not at zero

I'm not having any problems, so I'm not worried, but I'm just wondering...whereabouts is a good area for that gauge? At about 650-700RPM (idle in gear with A/C on) the gauge is at the first 1/4 tick; upping it to about 1000-1100RPM brings it to half and it increases slower from there. I don't think it goes above the third mark, even to 5500RPM, but that gauge is the least of my worries then

Anyway...it's a somewhat tired 135,500mi 33-year-old 350 with 20w50 oil. Normal? High? Low? Surprised it's not squirting everywhere / seized?

68 Suburban · 05-27-2003, 06:05 AM

Sound correct to me.

Long Knight · 05-27-2003, 09:26 AM

20w50? Leak and smoke a little?

Before my rebuild my pressure was about where yours is, no problems. After my new pump I'm at half way when warm, almost all the way right when rpm's are up.

Project1970 · 05-27-2003, 09:58 AM

Read the miles and age again. Add 100-degree temps and I think I'd consider thicker oil if it existed.

Long Knight · 05-27-2003, 10:08 AM

I knew of a guy, had a car that leaked and burned oil so bad he carried a five gallon can of used (tractor) oil in his trunk! Mine had a few more miles than yours before the rebuild and it was a heavily used farm truck before I got it, so I can feel your pain. If you ever tear it apart you'll love the smell!

da-burb · 05-27-2003, 05:50 PM

Consider it normal. The gauge is 60psi at the last mark. So 15psi at idle is plenty. I believe I have read that it can be as low as 5#'s at idle and still function. The old rule I grew up with was 10psi per 1000rpm's.

And as far as leaky, smudge pot burning autos goes, a kid back in highschool had a Vega. He mounted a 30 gallon barrel on the roof. His family ran the Standard Gas station so he had plenty of waste oil to burn. If the oil light came on he only had to turn the valve open until the light went out.

cableguy0 · 05-27-2003, 07:44 PM

ok not to highjack this thread but does anyone know how much pressure all the marks on the stock mechanical guage are.

1969 GMC · 05-27-2003, 07:55 PM

yeah i'd like to know that also.

cableguy0 · 05-27-2003, 09:10 PM

come on guys someone has to know what each mark designates pressure wise

Brad · 05-27-2003, 09:14 PM

I think it's 15, 30, 45, 60. I'm away from the truck right now, so someone correct me if I'm wrong.

da-burb · 05-27-2003, 10:28 PM

you forgot the first one........0 zero. There were some trucks that came with 80psi gauges also. I would like to find a nice one for my burb. With the new oil pump it will bury the needle out of sight.

cableguy0 · 05-27-2003, 10:52 PM

ok so ur saying the first mark is definately no pressure whatsoever

because after real hard highway runs it has went down to the first mark after coming to a stop this rebuild isnt that old im running 10w30 amsoil and it pegs the guage on startup even when its fairly warm out

lukecp · 05-27-2003, 11:23 PM

I have taken out the pressure guage from the dash before and it reads "DELCO 60 PSI", so the bottom tick is 0psi, 1st is 15, 2nd is 30, 3rd is 45, and the last is 60. So if the guage is bottomed out, you have zero oil pressure

cableguy0 · 05-27-2003, 11:36 PM

i gotta go look at my gauge and make sure im looking at it right it woulda locked up with zero oil pressure i know damn well

05-27-2003, 06:04 AM	#1
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	Oil pressure question I just realized I'd never paid attention to exactly where my oil pressure gauge sits, especially when hot...all I do is make sure it's not at zero I'm not having any problems, so I'm not worried, but I'm just wondering...whereabouts is a good area for that gauge? At about 650-700RPM (idle in gear with A/C on) the gauge is at the first 1/4 tick; upping it to about 1000-1100RPM brings it to half and it increases slower from there. I don't think it goes above the third mark, even to 5500RPM, but that gauge is the least of my worries then Anyway...it's a somewhat tired 135,500mi 33-year-old 350 with 20w50 oil. Normal? High? Low? Surprised it's not squirting everywhere / seized? __________________ Project1970 - LS1 Swap Complete!

05-27-2003, 06:05 AM	#2
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	Sound correct to me. __________________ Just sitting here contemplating contemplation.

05-27-2003, 09:26 AM	#3
Long Knight Spank 'em if you got 'em! Join Date: Nov 2002 Location: Kansas City Posts: 628	20w50? Leak and smoke a little? Before my rebuild my pressure was about where yours is, no problems. After my new pump I'm at half way when warm, almost all the way right when rpm's are up. __________________ Long Knight '71 C-20, 350ci, TH350, Edl. 1406 Carb w/elec.choke, Ignitor ignition, Viper Tires, Orange Dipstick

05-27-2003, 09:58 AM	#4
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	Read the miles and age again. Add 100-degree temps and I think I'd consider thicker oil if it existed. __________________ Project1970 - LS1 Swap Complete!

05-27-2003, 10:08 AM	#5
Long Knight Spank 'em if you got 'em! Join Date: Nov 2002 Location: Kansas City Posts: 628	I knew of a guy, had a car that leaked and burned oil so bad he carried a five gallon can of used (tractor) oil in his trunk! Mine had a few more miles than yours before the rebuild and it was a heavily used farm truck before I got it, so I can feel your pain. If you ever tear it apart you'll love the smell! __________________ Long Knight '71 C-20, 350ci, TH350, Edl. 1406 Carb w/elec.choke, Ignitor ignition, Viper Tires, Orange Dipstick

05-27-2003, 05:50 PM	#6
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	Consider it normal. The gauge is 60psi at the last mark. So 15psi at idle is plenty. I believe I have read that it can be as low as 5#'s at idle and still function. The old rule I grew up with was 10psi per 1000rpm's. And as far as leaky, smudge pot burning autos goes, a kid back in highschool had a Vega. He mounted a 30 gallon barrel on the roof. His family ran the Standard Gas station so he had plenty of waste oil to burn. If the oil light came on he only had to turn the valve open until the light went out. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

05-27-2003, 07:44 PM	#7
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	ok not to highjack this thread but does anyone know how much pressure all the marks on the stock mechanical guage are. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

05-27-2003, 07:55 PM	#8
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	yeah i'd like to know that also. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

05-27-2003, 09:10 PM	#9
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	come on guys someone has to know what each mark designates pressure wise __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

05-27-2003, 09:14 PM	#10
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	I think it's 15, 30, 45, 60. I'm away from the truck right now, so someone correct me if I'm wrong. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

05-27-2003, 10:28 PM	#11
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	you forgot the first one........0 zero. There were some trucks that came with 80psi gauges also. I would like to find a nice one for my burb. With the new oil pump it will bury the needle out of sight. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

05-27-2003, 10:52 PM	#12
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	ok so ur saying the first mark is definately no pressure whatsoever because after real hard highway runs it has went down to the first mark after coming to a stop this rebuild isnt that old im running 10w30 amsoil and it pegs the guage on startup even when its fairly warm out __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

05-27-2003, 11:23 PM	#13
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	I have taken out the pressure guage from the dash before and it reads "DELCO 60 PSI", so the bottom tick is 0psi, 1st is 15, 2nd is 30, 3rd is 45, and the last is 60. So if the guage is bottomed out, you have zero oil pressure __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

05-27-2003, 11:36 PM	#14
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	i gotta go look at my gauge and make sure im looking at it right it woulda locked up with zero oil pressure i know damn well __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

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