Oil Pressure at Idle - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JOJABOY · 03-21-2013, 08:43 AM

My oil gauge drops to L when at idle. Then comes up to center of gauge while driving. Dipstick reads full so I haven't worried much.

Just curious where everyone else's gauge reads at idle.
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*dajn* · 03-21-2013, 09:25 AM

My 72 is the same way. 350 engine. Not sure on rpm's at idle.
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b.eddy's72 · 03-21-2013, 11:20 AM

Mine does the same. If im not mistaken a sb chevy needs 8psi per 1000 rpms minimum. I have never read it anywhere but a buddy told me that has built race engines all his life. Mine when hot idels about 15-20psi

**JJorgensen52** · 03-21-2013, 11:44 AM

Same, right around 22lbs hot at idle.

What weight of oil are you running?

bronze 72 super · 03-21-2013, 12:33 PM

If memory serves me right, small block Chevy's should idle right around 25-30 p.s.i. Weight of oil will effect this. A stock pump put's out this much. I prefer to run a straight 30 weight with these older motors, that's what was recommend back then. Colder temperature run a multiweight oil. I run a high pressure, high volume pump in my '70 El Camino small block 350. It runs around 30-40 p.s.i. at idle, about 50-60 at highway speeds, I've been running this type of pump for years in a lot of my small blocks, dosn't effect them at all.

vidman · 03-21-2013, 12:45 PM

Before pulling my 402 It was around 20-25 lbs at Idle

BADPURPLE70CHEVY · 03-21-2013, 01:28 PM

10 psi for every 1,000 rpm.

cdowns · 03-21-2013, 01:34 PM

old hi milage small block chevys it is VERY VERT COMMON to have little to no oil pressure at idle and have the engine run just fine for a few hundred thousand at that point and beyond

scrappy · 03-21-2013, 01:57 PM

Quote:

Originally Posted by BADPURPLE70CHEVY

10 psi for every 1,000 rpm.

Thats what I've always heard... I have a 72 nova that had a mild 350. The guy I got it from assembled the engine himself. It had 60psi while driving but the only thing that bothered me about it was that the oil pressure would drop to about 10psi at idle after long drives. One day while getting on it going down a freeway on ramp it blew the front main seal. I towed it home & pulled the engine to put in a one piece oil pan gasket. When I pulled the pan I noticed that the oil pump pick-up had been touching it so it was being starved of oil. Every rod & crank bearing was showing copper & the crank was scored. To make a short story long I'm not trying to scare you but this is just something to think about.

budman k20 · 03-21-2013, 02:24 PM

Before my oil change the needle in my stock gauge would be about 1/4 below the first line. I just changed my oil and filter using 10w-30w dino oil (previous oil was the same) and I went from a Fram HP to a Wix filter and now after several heat cycles with the engine at operating temp, my in gear idle (600rpm) oil pressure is a little past (1/4) the first line. I had 918 miles on the oil when I changed it so I dont think it was the oil. I plan on buying Wix filters in the future!

GRX · 03-21-2013, 06:01 PM

Quote:

Originally Posted by BADPURPLE70CHEVY

10 psi for every 1,000 rpm.

Until the bypass valve relief spring kicks in and it starts dumping excess oil back into the system. Usually around 60psi. The idiot light (no gauge) doesn't come on until the pressure drops below 5psi or so.

Dnrice · 07-07-2013, 02:20 PM

Just put oil gauge on. My gauge doesn't read hardly at all until I stop. Do you think something is wrong? I was running it without a gauge connected.

weaintscared · 07-08-2013, 09:49 PM

I just cranked my new motor for the first time and it running 80 at an idle

My build http://67-72chevytrucks.com/vboard/s...d.php?t=468622
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chopnchaneled · 07-09-2013, 02:40 PM

On a hot georgia day after xway driving, mine is 40lbs at speed and 15 at the red light on the exit ramps, touch the gas and back up to 40. thats using 20-50 mobile 1 full syn.

Rufton · 07-09-2013, 04:12 PM

One way to check idle oil pressure is to remove valve covers and make sure each rocker arm is getting oil. 10 psi per 1000 rpm is a good rule of thumb provided gauge is accurate, oil galleys are clean and clearances are reasonable.

YOUNG GUN C10 · 07-09-2013, 07:32 PM

I thought the same thing about mine...it idles about 600 rpm... but at 600 rpm, it only needs 6 psi of oil pressure... given the 10 psi per 1,000 rpm rule of thumb... i changed the oil from 10w-30 to 15w-40 just because i didnt like the low oil pressure, but it didnt change the idle oil pressure any that i could tell(stock gauge) lol

Hubscrub · 07-09-2013, 09:39 PM

small block chevy don't need much at idle, if it ain't knocking you have oil pressure

70c10stepside · 07-09-2013, 10:31 PM

Mine sits at 30-45 at idle.
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Toxic Orange · 07-09-2013, 11:51 PM

Mine is scary low at full temperature idle. I have an aftermarket set of gauges (reasonably cheap set). It does not knock and gives no audible signs of stress but will get down to lower than 5. Currently running Castroil 10-30 and a Wix filter. Stock gauge is also hooked up and reads about a 1/4 when at idle. I have been slightly worried but knowing it does not take much to keep it lubricated properly. Mine is a SB 350.

03-21-2013, 08:43 AM	#1
JOJABOY Registered User Join Date: Sep 2012 Location: Factory Posts: 681	Oil Pressure at Idle My oil gauge drops to L when at idle. Then comes up to center of gauge while driving. Dipstick reads full so I haven't worried much. Just curious where everyone else's gauge reads at idle. Posted via Mobile Device

03-21-2013, 09:25 AM	#2
dajn Account Suspended Join Date: Feb 2011 Location: Ogilvie Minnesota Posts: 461	Re: Oil Pressure at Idle My 72 is the same way. 350 engine. Not sure on rpm's at idle. Posted via Mobile Device

03-21-2013, 11:20 AM	#3
b.eddy's72 Registered User Join Date: Nov 2009 Location: WEATHEROFRD, TX Posts: 164	Re: Oil Pressure at Idle Mine does the same. If im not mistaken a sb chevy needs 8psi per 1000 rpms minimum. I have never read it anywhere but a buddy told me that has built race engines all his life. Mine when hot idels about 15-20psi __________________ 72 Chevy LB, LS in the works, 4L80, Grandfather bought it brand new. 66 GMC Short Step, 84 Front Suspension, many more mods to come 67 Chevy 3/4 Ton, 327, Auto, Factory A/C Ya must have been movin cause I was haulin a*$ when I passed you

03-21-2013, 11:44 AM	#4
JJorgensen52 Simple? What's simple? Join Date: Apr 2007 Location: Southeast CT Posts: 1,472	Re: Oil Pressure at Idle Same, right around 22lbs hot at idle. What weight of oil are you running? __________________ CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder)

03-21-2013, 12:33 PM	#5
bronze 72 super Registered User Join Date: Sep 2007 Location: Rufus Oregon Posts: 1,187	Re: Oil Pressure at Idle If memory serves me right, small block Chevy's should idle right around 25-30 p.s.i. Weight of oil will effect this. A stock pump put's out this much. I prefer to run a straight 30 weight with these older motors, that's what was recommend back then. Colder temperature run a multiweight oil. I run a high pressure, high volume pump in my '70 El Camino small block 350. It runs around 30-40 p.s.i. at idle, about 50-60 at highway speeds, I've been running this type of pump for years in a lot of my small blocks, dosn't effect them at all.

03-21-2013, 12:45 PM	#6
vidman Registered User Join Date: Jun 2012 Location: Fitchburg,Mass Posts: 737	Re: Oil Pressure at Idle Before pulling my 402 It was around 20-25 lbs at Idle __________________ 62 Willys 4wd Pickup : 72 C-10 swb 504 stroker 09 Taco 3" lift 33" tires: 90 K-5 blazer (plow truck): RIP Ross Little brother

03-21-2013, 01:28 PM	#7
BADPURPLE70CHEVY 406 Powered Join Date: Aug 2009 Location: waynesville,n.c. Posts: 877	Re: Oil Pressure at Idle 10 psi for every 1,000 rpm. __________________ 70 GMC 68 c10 2002 silverado 72 4x4

03-21-2013, 01:34 PM	#8
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Oil Pressure at Idle old hi milage small block chevys it is VERY VERT COMMON to have little to no oil pressure at idle and have the engine run just fine for a few hundred thousand at that point and beyond __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-21-2013, 02:24 PM	#10
budman k20 1972 K20 Join Date: Apr 2008 Location: Greenfield MN Posts: 360	Re: Oil Pressure at Idle Before my oil change the needle in my stock gauge would be about 1/4 below the first line. I just changed my oil and filter using 10w-30w dino oil (previous oil was the same) and I went from a Fram HP to a Wix filter and now after several heat cycles with the engine at operating temp, my in gear idle (600rpm) oil pressure is a little past (1/4) the first line. I had 918 miles on the oil when I changed it so I dont think it was the oil. I plan on buying Wix filters in the future!

07-07-2013, 02:20 PM	#12
Dnrice Registered User Join Date: Nov 2012 Location: Spartanburg SC Posts: 87	Re: Oil Pressure at Idle Just put oil gauge on. My gauge doesn't read hardly at all until I stop. Do you think something is wrong? I was running it without a gauge connected.

07-08-2013, 09:49 PM	#13
weaintscared Registered User Join Date: Mar 2011 Location: Sumter SC Posts: 439	Re: Oil Pressure at Idle I just cranked my new motor for the first time and it running 80 at an idle My build http://67-72chevytrucks.com/vboard/s...d.php?t=468622 Posted via Mobile Device

07-09-2013, 02:40 PM	#14
chopnchaneled Registered User Join Date: Dec 2009 Location: Atlanta, Ga. Posts: 1,050	Re: Oil Pressure at Idle On a hot georgia day after xway driving, mine is 40lbs at speed and 15 at the red light on the exit ramps, touch the gas and back up to 40. thats using 20-50 mobile 1 full syn. __________________ I don't think we get smarter as we get older. We just run out of Stupid things to do.

07-09-2013, 04:12 PM	#15
Rufton Registered User Join Date: Apr 2013 Location: Knoxville TN Posts: 1,170	Re: Oil Pressure at Idle One way to check idle oil pressure is to remove valve covers and make sure each rocker arm is getting oil. 10 psi per 1000 rpm is a good rule of thumb provided gauge is accurate, oil galleys are clean and clearances are reasonable.

07-09-2013, 07:32 PM	#16
YOUNG GUN C10 Registered User Join Date: Jul 2013 Location: Campton Kentucky Posts: 11	Re: Oil Pressure at Idle I thought the same thing about mine...it idles about 600 rpm... but at 600 rpm, it only needs 6 psi of oil pressure... given the 10 psi per 1,000 rpm rule of thumb... i changed the oil from 10w-30 to 15w-40 just because i didnt like the low oil pressure, but it didnt change the idle oil pressure any that i could tell(stock gauge) lol

07-09-2013, 09:39 PM	#17
Hubscrub Cruzin Join Date: Dec 2009 Location: on the road Posts: 2,835	Re: Oil Pressure at Idle small block chevy don't need much at idle, if it ain't knocking you have oil pressure __________________ Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14



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07-09-2013, 10:31 PM	#18
70c10stepside Registered User Join Date: Jun 2011 Location: Taylorsville, Georgia Posts: 482	Re: Oil Pressure at Idle Mine sits at 30-45 at idle. Posted via Mobile Device

07-09-2013, 11:51 PM	#19
Toxic Orange Registered User Join Date: Apr 2013 Location: Flower Mound TX Posts: 173	Re: Oil Pressure at Idle Mine is scary low at full temperature idle. I have an aftermarket set of gauges (reasonably cheap set). It does not knock and gives no audible signs of stress but will get down to lower than 5. Currently running Castroil 10-30 and a Wix filter. Stock gauge is also hooked up and reads about a 1/4 when at idle. I have been slightly worried but knowing it does not take much to keep it lubricated properly. Mine is a SB 350.

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