oil pressure
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
Twice that and some unless your idle is well below spec. That is usually a sign of a high miler, too much pressure loss at bearings for pump to keep up at low idle, hot/thin oil. Probably a good time to consider going up a grade in oil (ie go to 15/40).. Is this car high mileage or poorly maintained? If it's lower mileage and has always had changes on time, you may need to look closer.
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
What's it show at 2500+ RPM? Remember, oil consumption is rings or leaks, not your problem. Low pressure is worn bearings, weak pump or oil thinned by gas.
Certainly a good idea to verify the gauge is right or wrong, either hook up a mechanical gauge or find the ohm readings the sender should produce. Since the sender on these things is beyond ignorant to get to....
Do you ever have issues where when it is really hot it cranks longer than expected before it starts? If yes, I wouldn't bother testing the sender.. You have a sender to flip the gauge and another sensor that won't allow the car to start unless it sees 5lbs (or something) while cranking. Odds are they won't both go south at the same time.
Certainly a good idea to verify the gauge is right or wrong, either hook up a mechanical gauge or find the ohm readings the sender should produce. Since the sender on these things is beyond ignorant to get to....
Do you ever have issues where when it is really hot it cranks longer than expected before it starts? If yes, I wouldn't bother testing the sender.. You have a sender to flip the gauge and another sensor that won't allow the car to start unless it sees 5lbs (or something) while cranking. Odds are they won't both go south at the same time.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
If you have at least 35-40 Psi oil pressure at 2,600 RPM's driving down the road, you probably are ok.
Mobil 1 5w30 oil is pretty thin stuff.
They recommend the the same weight 5w30 oil in my 87 vert.
I use 10w30 oil.
I have 65-70psi oil pressure at 2,600RPM's with engine oil and coolant hot.
At idle after alot of highway driving or high speed runs when the engine oil is over 200 degrees F, I will see about 22psi oil pressure in Drive, foot on the brake, and engine idling at 600-700RPM's.
Might be a good time to check the oil pressure sender on your Vette or replace it.
Then recheck.
I replaced the original oil pressure sender on my 87 with a NOS GM part.
I didnt believe my engine had that good of oil pressure- 70psi peak hot.
If your Vette doesnt use any engine oil, the Main bearings, connecting rod bearings, and cam bearings are most likely OK & in good shape yet.
Crankshaft journals would be in nice condition yet too.
My 87 Vette doest use a drop of oil either, even after 3,000 miles of driving. Much of it at very high speeds.
BR
Mobil 1 5w30 oil is pretty thin stuff.
They recommend the the same weight 5w30 oil in my 87 vert.
I use 10w30 oil.
I have 65-70psi oil pressure at 2,600RPM's with engine oil and coolant hot.
At idle after alot of highway driving or high speed runs when the engine oil is over 200 degrees F, I will see about 22psi oil pressure in Drive, foot on the brake, and engine idling at 600-700RPM's.
Might be a good time to check the oil pressure sender on your Vette or replace it.
Then recheck.
I replaced the original oil pressure sender on my 87 with a NOS GM part.
I didnt believe my engine had that good of oil pressure- 70psi peak hot.
If your Vette doesnt use any engine oil, the Main bearings, connecting rod bearings, and cam bearings are most likely OK & in good shape yet.
Crankshaft journals would be in nice condition yet too.
My 87 Vette doest use a drop of oil either, even after 3,000 miles of driving. Much of it at very high speeds.
BR
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
If you are using synthetic oil , switch to a blended, I know mobile 1 is good , its just not good for older engines. I put some in my 87 when I first got it and lost 10 psi oil pressure, thought for a minute i was driving a ford. if you're using a Fram oil filter , get something else.
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
Sandpiper is half correct. The second sensor is a fuel system fail safe. Provides power to the pump if the primary system fails while the engine is running. A limp home feature.
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Advanced
Joined: Jan 2005
Posts: 63
Likes: 0
From: Southgate Mi.
Buy, or borrow a mechanical gauge to check it with. Mine was low like yours, so I dumped in some Lucas (I knew it needed a rebuild anyway). After that the pressure was rediculus! 80 psi above idle. Upon removal and inspection the bearings were cooked, but mine had 120k.
Good Luck!
Good Luck!