Topic: Oil Pressure Fluctuations
in Forum: C3 Engines
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Lifetime MemberLemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
I got the car idling down about where it is supposed to when
warm 600 to 650. It runs ruff at that
speed but settles out about 750 or above. When it is warm (190-200 degrees never runs
hotter than 200) the oil pressure gage at idle fluctuates between 25 and 40
pounds. Around 950 up it is smooth and
over 40 pounds. Car is currently about ½ quart
of oil down is all so that should not be the problem.
General information car only has 46000 miles on it. Sat for 4 years before I got it 4 years ago in those 4 years I have only put about 2000 miles on it. But now drive it 3 or 4 times a week as it is my preferred mode of transportation.
I’m concerned and would like to know what is the recommended place to start and or possible causes.
General information car only has 46000 miles on it. Sat for 4 years before I got it 4 years ago in those 4 years I have only put about 2000 miles on it. But now drive it 3 or 4 times a week as it is my preferred mode of transportation.
I’m concerned and would like to know what is the recommended place to start and or possible causes.
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Lifetime MemberIndianapolis, IN - USA
Joined: 9/3/2006
Posts: 2429
Vette(s): Silver 1974 Convertible - L82 4 speed
Low miles (was only 8,900 when I bought it in March 2006) - Now 54K miles. Original owner bought it as an investment for son's college expenses.
2008 Jetstream Blue Convertible
How confident are you that the gague is accurate?
I wanted a Corvette my whole life, but I never dreamed of all the wonderful people I would meet because of it!
2014216132127r.jpg)
Lifetime MemberLemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
I used to be less confident before I got the idle down close to where it is suppose to be because above 950 rpm the oil pressure needle is rock solid at a little over 40 psi. Now down a idle it oscillates between 25 and 40. most of the time swinging fast enough that you cannot see the needle between the upper and lower limits. It does not stay at the 25 mark more than a few tens of a second.
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
I would seriously consider installing a temporary, mechanical gauge to see what the actual oil pressure is. The fluctuating could be simply a defective pressure sending unit, which would be my first guess, but it could also be the gauge itself, or...worst case, an actually oil pressure problem. The mechanical gauge will tell the tale quickly.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Is that the official Double E solution, Dave?
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberLemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
That is so simple. I just cannot figure out how I missed that. 
Double thanks to you now I can fix my Toyota problem only occurs when I'm driving the Toyota. The solution is so obvious and it can be applied to all problems. LOL. 
I just will not drive it anymore. (trade cars with my wife)
Double thanks to you now I can fix my Toyota problem only occurs when I'm driving the Toyota. The solution is so obvious and it can be applied to all problems. LOL. I just will not drive it anymore. (trade cars with my wife)
Now THAT"S the way to fix it! 
Barry
Hi Gilbert,
I have had the same kind of shaking oil needle since I've had Baby. It happens around idle and when I'm driving down the road. Mostly, I notice it when I'm off the throttle. The oil temp does not spike and there is no change in the water temp. I don't hear any difference in sound or in performance. The techs I've talked to said it sounds like a bad meter or sender sensitive to a harmonic or whatever. I have not pulled the oil pan yet but, there is rust working on it so, that will happen some time...... They did not seem think it was a big deal because of the steady temps....
So, this post won't help any...
Keith
I have had the same kind of shaking oil needle since I've had Baby. It happens around idle and when I'm driving down the road. Mostly, I notice it when I'm off the throttle. The oil temp does not spike and there is no change in the water temp. I don't hear any difference in sound or in performance. The techs I've talked to said it sounds like a bad meter or sender sensitive to a harmonic or whatever. I have not pulled the oil pan yet but, there is rust working on it so, that will happen some time...... They did not seem think it was a big deal because of the steady temps....
So, this post won't help any...
Keith
Nobody ever waves when I'm driving the Explorer.
K Woody
Lifetime MemberLemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
Thanks I plan on checking it with oil pressure gage in the near future will let everyone know what it looks like then just in case others have the same problem.
Gil
Gil
in Forum: C3 Engines
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