Oil Pressure
Thread Starter
Pro
Joined: Sep 2014
Posts: 588
Likes: 35
From: Smithfield VA
Oil Pressure
Ok, so getting to know my '93 that I just bought, I have a question.
'93 LT1 w/ 6spd man and around 150k miles
When the car is started up and still cold, it seems to have extremely high oil pressure. At a 1000-1500 RPMs, the oil pressure gauge needle is at 3/4 reading. 2000 RPMs or more, and the gauges needle is buried as far as it will go. After the car properly warms up, at 1000-1500 RPMs, the needle is only showing a reading of 1/4, and at WOT, the pressure is only at the 3/4 mark. (I hope you guys and girls understand what I'm saying here. If need be, I can take pics of the gauge showing what I'm talking about)
Is this something I should be concerned about? I do not know exactly what brand or weight oil is in the car. All I do know about it is it looks new and very clean. Also, when looking at the top of the heads though the oil cap hole, the top of the heads are also very clean looking. The car runs great with no knocking or tapping of any kind.
'93 LT1 w/ 6spd man and around 150k miles
When the car is started up and still cold, it seems to have extremely high oil pressure. At a 1000-1500 RPMs, the oil pressure gauge needle is at 3/4 reading. 2000 RPMs or more, and the gauges needle is buried as far as it will go. After the car properly warms up, at 1000-1500 RPMs, the needle is only showing a reading of 1/4, and at WOT, the pressure is only at the 3/4 mark. (I hope you guys and girls understand what I'm saying here. If need be, I can take pics of the gauge showing what I'm talking about)
Is this something I should be concerned about? I do not know exactly what brand or weight oil is in the car. All I do know about it is it looks new and very clean. Also, when looking at the top of the heads though the oil cap hole, the top of the heads are also very clean looking. The car runs great with no knocking or tapping of any kind.
Last edited by 1stVetteFinally; Feb 10, 2018 at 10:05 AM.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
You will want to test the pressure of your engine independent of your analog gauge. The fact that you are getting wild swings tell me that your gauge is messed. The gauges are not really very accurate.
So, 1) clean your contact points, 2) you could replace the sending unit, 3) test independently.
So, 1) clean your contact points, 2) you could replace the sending unit, 3) test independently.
Thread Starter
Pro
Joined: Sep 2014
Posts: 588
Likes: 35
From: Smithfield VA
how would I do this?
I don't know if I would call what I'm seeing as "wild swings" as the amount of pressure shown is in relation with the RPMs of the car. More RPMs, the pressure goes up, less RPMs, the pressure goes down. It's just the huge difference in pressure readings between being cold and warm that has me concerned
I don't know if I would call what I'm seeing as "wild swings" as the amount of pressure shown is in relation with the RPMs of the car. More RPMs, the pressure goes up, less RPMs, the pressure goes down. It's just the huge difference in pressure readings between being cold and warm that has me concerned
Last edited by 1stVetteFinally; Feb 10, 2018 at 10:21 AM.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
It actually seems pretty normal to me. The way you describe the gauge is within observable specs (a fancy way to say "look ok")
I mention the test IF you are concerned. Short of the tests, clean the contacts or get a new pressure switch.
If it were me, I'd grab a beer and not worry about it- you seem good.
I mention the test IF you are concerned. Short of the tests, clean the contacts or get a new pressure switch.
If it were me, I'd grab a beer and not worry about it- you seem good.
Team Owner
Joined: Jul 2004
Posts: 28,372
Likes: 3,260
From: Hartford WI
how would I do this?
I don't know if I would call what I'm seeing as "wild swings" as the amount of pressure shown is in relation with the RPMs of the car. More RPMs, the pressure goes up, less RPMs, the pressure goes down. It's just the huge difference in pressure readings between being cold and warm that has me concerned
I don't know if I would call what I'm seeing as "wild swings" as the amount of pressure shown is in relation with the RPMs of the car. More RPMs, the pressure goes up, less RPMs, the pressure goes down. It's just the huge difference in pressure readings between being cold and warm that has me concerned
Melting Slicks
Joined: Sep 2005
Posts: 2,670
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From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
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Since you don't know what oil is in the car, I'd do a change first. Then see what happens. The previous owner might have put much higher viscosity oil in there.
Team Owner
Joined: Jul 2004
Posts: 28,372
Likes: 3,260
From: Hartford WI
Good point. I know of people who put high viscosity oil and some of those "Motor Honey" or STP to thicken the oil just so it doesn't sound noisy at time of sale.
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Zen Vet Master Level VII
Joined: Mar 2016
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From: Southlake, TX
