Oil pressure

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Oct 15, 2010 | 06:31 PM

swensonm

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Racer

Joined: Nov 2005

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From: San Antonio TX

Oil pressure

I have a 74 L82 (stock gauge) I have checked search and cant find what I am looking for...
At idle it looks about 40 to 45 psi at 70 mph I am running about 60-65 is that normal. For some reason I was thinking it was lower in the past.
Thanks

Oct 15, 2010 | 06:46 PM

78 C3 Light Corvette Blue

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From: La Porte In

I have 78 L82 and is right there also. 40 idle 60 -65 highway
10w30 SynPower, living in North West Indiana. Car stored Nov1 through April

Last edited by 78 C3 Light Corvette Blue; Oct 16, 2010 at 03:48 PM.

Oct 15, 2010 | 07:28 PM

wnmech

Drifting

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From: grand prairie texas

My 77 at around 60 mph my oil pressure will hold steady at also 60 PSI and at idle it is usually at 30PSI with the engine at operating temperature

Oct 15, 2010 | 07:29 PM

TimAT

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From: Gladstone MO

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One of those places that a little more is better than not quite enough...

Oct 15, 2010 | 10:17 PM

coconut vette

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From: Tamuning Guam

I have a 77' and eng is ported. I am running around 75 @ 60 mph. Sounds too high? What may be the cause for high oil pressure. Anyone can help since we are on this subject of oil pressure? Engine runs great just concern that pressure is too high?

Oct 15, 2010 | 11:30 PM

sturgeongeneral

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From: Sacramento ca

Quote:

Originally Posted by coconut vettre

Too thick of oil can cause excessive pressure. And yes, too much pressure can be bad also.

Oct 15, 2010 | 11:48 PM

TimAT

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From: Gladstone MO

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FWIW: I run 30w oil, get 70+ PSI over 3000 RPM and idle at 35-40PSI. (ZL-1 oil pump)

Oct 16, 2010 | 01:47 AM

eatmydst1234

Burning Brakes

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Quote:

Originally Posted by TimAT

FWIW: I run 30w oil, get 70+ PSI over 3000 RPM and idle at 35-40PSI. (ZL-1 oil pump)

The LS7 in my '69 chevelle runs around 50 at idle warmed up, I see around 80-85 over 3000 RPM's

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Oct 16, 2010 | 05:11 AM

coconut vette

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From: Tamuning Guam

i am in warm tropic weather running 15-50 mobil 1, should i go to 5-30? so 80-85 is still ok as some of you seem to be around there? thanks for the info. No winter here.

Oct 16, 2010 | 09:02 AM

#10

TimAT

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From: Gladstone MO

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5wt is pretty thin. I wouldn't go any less than 15.

Oct 16, 2010 | 09:50 AM

#11

swensonm

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From: San Antonio TX

Thanks for the info

I guess I got worked up for nothing. Maybe I was mistaken that is is higher that i remember. I guess I will change the oil/filter and watch it!
I was surprized that I could not find a range in the chevy manual!
\
Mike

Oct 16, 2010 | 11:41 AM

#12

wheatpj

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From: St. James, NC

Quote:

Originally Posted by TimAT

5wt is pretty thin. I wouldn't go any less than 15.

I use Mobel 1 15W-50 in Ohio. I keep my driving to 50+ degree days...why drive your C3 if you can't roll down the windows. Seriously, those thinner oils are designed for newer engines with tighter tolerances than our old C3s. I get 35 at idle and 65 above 2500 when the oil is hot. I won't go any lower the 10w-30.

Oct 16, 2010 | 06:56 PM

#13

coconut vette

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From: Tamuning Guam

I'll stay with 15-50 on mine. Is there a possibility that the pressure sending unit can malfunction, clog, get dirty and give false reading? Can they be cleaned or must replace?

Oct 16, 2010 | 07:45 PM

#14

TimAT

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The senders have been known to go bad, but the usual mode of failure is a zero or really low reading.

Oct 17, 2010 | 05:14 AM

#15

coconut vette

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From: Tamuning Guam

Hey TimAT, Appreciate the info. Thanks

Oct 17, 2010 | 09:13 AM

#16

Paul L

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From: Ontario

Quote:

Originally Posted by swensonm

From the 1974 Owner's Manual:

Readings of 30 to 40 psi may be considered normal during moderate road speeds of 35 to 40 mph with the engine at proper operating temperature.

Mine is about 45 psi at speed and 25 psi at idle; this with Castrol 10W-30.

Oct 17, 2010 | 01:22 PM

#17

swensonm

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Racer

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From: San Antonio TX

oil

Paul
Is that for L48 or 82.
Mike
Gonna check my owners book.
That make me wonder why mine is so high (comparitively)
40+ at idle
60+ at 3 grand

Oct 17, 2010 | 02:47 PM

#18

jb78L-82

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From: RI, Now Franklin/Nashville TN

My 78 L-82 with Mobil 1 15W-50 is 40 at idle up to about 50-55 when running. It has always read that way, 27 years owned and 65,000 miles. It has never read over 60 PSI when hot, only when cold. I would think that an OEM engine running pretty much over 55 PSI when hot at speed means either the gauge is wrong or something else is up. I know other 78/79 L-82 owners who report my oil pressure so if you are seeing 60, 65, 70 psi, as I said, something does not seem right.

Oct 17, 2010 | 02:55 PM

#19

glen242

Melting Slicks

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From: Moon Twp. PA USA

Quote:

Originally Posted by swensonm

Is this a new engine and/or did you change something that could effect the oil pressure?

I had a bad sending unit and replaced it with an Autozone unit. Oil pressure went way high at idle and at speed. Bought a $10 manual gauge which read correctly. I used a resistor in the stock gauge line until I got the reading to match the mechanical gauge.

Oct 17, 2010 | 10:04 PM

#20

mj9311

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From: bethpage NY

Quote:

Originally Posted by coconut vettre

I'll stay with 15-50 on mine. Is there a possibility that the pressure sending unit can malfunction, clog, get dirty and give false reading? Can they be cleaned or must replace?

if your concerned about cleaning it you should just replace it i just picked one up for 15 $

one wire and screw it out

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