Author Topic: C3 Oil pres question...  (Read 9986 times)

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Offline jolinari

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C3 Oil pres question...
« on: January 07, 2007, 02:09:52 AM »
I know for a fact the oil pres varies with speed and also the temperature of the air...according to my owner's manual, oil pres should be between 30-70 when travelling at 40-50 MPH and should be lower if you are travelling at higher speed

Can someone tell me please about the behaviour of the oil pres when increasing or decreasing the accelerator(for instance can you see the needle dropping when increasing speed or the other way around?)or when you are in neutral is it supposed to go down all the way?

I am just trying to determine whether my gauge is operating properly

thanks for your feedback

I am just bit concerned as i was driving to wollongong the temperature was soaring and on the way back it was heaps cooler and the needle was kind of really inconsistent and i was bit puzzled!

Offline Chromie

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C3 Oil pres question...
« Reply #1 on: January 07, 2007, 04:01:32 PM »
Hi jolinari :25
Usually you have maximum oil pressure once you get up to 1200 rpm or more
Engine oil pressure is controlled by RPM and oil temperature, outside air temperature has very little to do with the oil pressure (unless you live where it gets below zero).;27
Depending on what type of oil pump you have will depend upon what type of oil pressure you will get;46
An OEM type oil pump will give you from 15-20lbs at idle and up to 50lbs under throttle;35
An aftermarket oil pump especially a high pressure/high volumn oil pump will give you about 30-50lbs at idle and a constant 70 lib under throttle:luv
Hope this helps
Note a fluxuating oil pressure is the result of low engine oil level, or oil pump pick up loose/missing or a faulty oil pump pressure by-pass/relief valve;53

Offline Chromie

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C3 Oil pres question...
« Reply #2 on: January 07, 2007, 04:05:38 PM »
To test a oil pressure gauge you can do one of two things;46
1/ Put correct oil pressure gauge into the engine block and see what it reads and compare it to your oil pressure gauge in the dash
2/ If you have you oil pressure gauge out of the vehicle put air pressure to it via a pressure regulator and a correct pressure gauge and compare the readings of your Corvette gauge and the correct reading pressure gauge.
NOTE DO NOT PUT MORE THAT 70lbs INTO THE GAUGE AS IT WILL DAMAGE THE GAUGE.;38

Offline MADLT1

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C3 Oil pres question...
« Reply #3 on: January 07, 2007, 05:38:52 PM »
hey chromie do you sell any oil pressure gauges as mine is faulty:23

Offline Chromie

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C3 Oil pres question...
« Reply #4 on: January 07, 2007, 05:58:04 PM »
Quote
Originally posted by MADLT1
hey chromie do you sell any oil pressure gauges as mine is faulty:23


Hi MADLT1;42
I do not carry them in stock as they rarely require replacement;27
I take it that yours is seized (assuming that yours is pre 1973)
The 1973 and later were electric and so far have never been a problem.;35
We often have one's that are seized due to lack of use and so far we have repaired each one.:}
What is the problem with yours;38
If you require one I can get it in
Parts usually do not take any longer that 10 working days to get in.;29
If you require is quicker I can get the part in 3 working days or 5 working days but the freight charges are somewhat expensive.;37

Offline MADLT1

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C3 Oil pres question...
« Reply #5 on: January 07, 2007, 06:45:08 PM »
you hit the nail on the head chromie,mine is seized,what can we do?;42;42;42

Offline Chromie

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C3 Oil pres question...
« Reply #6 on: January 07, 2007, 06:54:22 PM »
Quote
Originally posted by MADLT1
you hit the nail on the head chromie,mine is seized,what can we do?;42;42;42


What we do is put machine oil (very fine lubricating oil) on the little wheel that the gauge uses to make the needle move.;27
The system is like a small party fluts that when you blow it it straightens up.:25
Same principal with the gauge:spook
Once the oil has time to lubricate (at least 24 hours) gently try to move the seized wheel/pivot, if it still won't move relubricate and keep repeating until it does.:luv
Once the needle is free test the gauge as previously stated above.:v
If you are not careful you will damage/break the gauge;38

Offline MADLT1

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C3 Oil pres question...
« Reply #7 on: January 07, 2007, 08:06:05 PM »
thanks chromie will give it a go through the week;42

Offline jolinari

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C3 Oil pres question...
« Reply #8 on: January 07, 2007, 10:39:45 PM »
Quote
Originally posted by Chromie
Hi jolinari :25
Usually you have maximum oil pressure once you get up to 1200 rpm or more
Engine oil pressure is controlled by RPM and oil temperature, outside air temperature has very little to do with the oil pressure (unless you live where it gets below zero).;27
Depending on what type of oil pump you have will depend upon what type of oil pressure you will get;46
An OEM type oil pump will give you from 15-20lbs at idle and up to 50lbs under throttle;35
An aftermarket oil pump especially a high pressure/high volumn oil pump will give you about 30-50lbs at idle and a constant 70 lib under throttle:luv
Hope this helps
Note a fluxuating oil pressure is the result of low engine oil level, or oil pump pick up loose/missing or a faulty oil pump pressure by-pass/relief valve;53


yep that helps and will check it out tomorrow :v

Offline Chromie

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C3 Oil pres question...
« Reply #9 on: January 09, 2007, 06:42:21 PM »
Quote
Originally posted by MADLT1
thanks chromie will give it a go through the week;42


Hi MADLT1:25
Let me know how you go with repairing your oil pressure gauge;42

Offline demonx

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C3 Oil pres question...
« Reply #10 on: January 09, 2007, 09:29:55 PM »
My oil pressure guage flutters around like crazy.

I'm assuming that the sensor is stuffed? I'm not too sure.

If thats what it is, are the sensors very expensive?

Offline Chromie

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C3 Oil pres question...
« Reply #11 on: January 10, 2007, 10:46:44 AM »
Quote
Originally posted by demonx
My oil pressure guage flutters around like crazy.

I'm assuming that the sensor is stuffed? I'm not too sure.


If thats what it is, are the sensors very expensive?


Hi demonx
First you will have to test the engine oil pressure

"To test a oil pressure gauge you put a correct reading mechanical oil pressure gauge into the engine block and see what it reads and compare it to your oil pressure gauge in the dash.;35

If the oil pressure reading result in normal oil pressure (no fluxuations) Then the oil pressure sending switch is at fault as this is the most common of faults with electric oil pressure gauges/switches;30
Hope this helps:v

The oil pressure switches which suit 1973-81 Corvettes are $141.10 + G.S.T. and I have them in stock

Offline demonx

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C3 Oil pres question...
« Reply #12 on: January 10, 2007, 03:54:24 PM »
Quote

Hi demonx
First you will have to test the engine oil pressure

"To test a oil pressure gauge you put a correct reading mechanical oil pressure gauge into the engine block and see what it reads and compare it to your oil pressure gauge in the dash.;35

If the oil pressure reading result in normal oil pressure (no fluxuations) Then the oil pressure sending switch is at fault as this is the most common of faults with electric oil pressure gauges/switches;30
Hope this helps:v

The oil pressure switches which suit 1973-81 Corvettes are $141.10 + G.S.T. and I have them in stock


Thanks for your help. Thats what I figured but since the topic was on oil guages I thought I'd throw it out there see what people said in case something else popped up.

I have a couple more important things on my list to do first, but when I get around to it I'll have to track down a pressure guage.