1995 Chevrolet S-10 oil pressure

1995 CHEVROLET S-10
289,000 MILES • 2.2L • 4 CYL • 2WD • MANUAL
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TRAVIS36701
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I've rebuilt my motor from the oil pickup tube all the way up to the valves and I need to know how much oil pressure it suppose to have at arm idle cause it drops down to 10 psi and below.. some people I've talked to says 10 - 20 or 30 - 50 at a warm idle but the book says 56 psi at 3k rpm.. not to mention if I try to drive it its stalls out if I let off the gas and that's when the oil pressure also falls to the red zone and the check gauges light comes on which my speedometer doesn't work so I'm not sure if the cluster is messed up or bad oil
Apr 7, 2014 at 7:37 AM
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JACOBANDNICKOLAS
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At an idle, 10psi isn't bad. I wouldn't expect it to go much above 60psi when driving. As far as the stalling, have you checked for vacuum leaks as well as the idle air control valve?
Apr 7, 2014 at 8:45 AM
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TRAVIS36701
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I know that I have a small vacuum hose unhooked cause I could not remember where it hooked up to which is right around the injectors are and I also noticed there's a small vacuum hose sticking up by the fender right around the firewall.. should there be a long hose running from there to the intake ?
Apr 7, 2014 at 9:09 AM
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JACOBANDNICKOLAS
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Without seeing where the hoses are coming from, that is hard to answer. However, I bet that the idle issue is the result of the leaks.
Apr 9, 2014 at 5:19 AM
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TRAVIS36701
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It pretty much lay on top the valve cover between the pcv valves that have like a plastic L inside of the hose like there suppose to be another hose hook up to it. but as for the oil pressure it dropped all the way to zero today and thinking maybe I bought a bad oil pump or either the drive gear is bad some how.. but someone also told me that I might be able to use a high volume oil pump for a 93 beretta 2.2 is that true or it won't bolt up ?
Apr 9, 2014 at 7:56 PM
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JACOBANDNICKOLAS
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We only recommend using direct fit parts. Question... when the oil pressure drops to 0, do you hear any knocking or ticking from the engine?
Apr 10, 2014 at 5:29 AM
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TRAVIS36701
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No I don't which I don't let it run long enough when it does drop to 0.. But also gotten my attention is when I turn my ignition off the oil gauge rises up to 20 psi and if I start it and let it run for few minutes it'll be at 80 psi than cut it off for a moment than it'll start up between 60 or 70 psi.. if I cut it off again it'll start up at 40 psi and every time I do it it'll keep starting at a lower psi which this is within 20 minutes time and the engine is barely warm but not hot engine where you can't touch it..
Apr 10, 2014 at 6:11 AM
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JACOBANDNICKOLAS
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I really think you have a bad sending unit. The best thing to do is to get a mechanical gauge (rent from parts store) and connected it to see if what you are seeing is really accurate. The mechanical gauge basically screws right into where the electric oil sensor is presently located. Since you don't hear any knocking or ticking, I don't feel the pressure is actually dropping to 0 psi. I think the oil pressure sensor (AKA sending unit) is bad or you have a poor or broken electrical connection to it.

Let me know if you have questions.
Apr 10, 2014 at 8:53 AM
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TRAVIS36701
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I've put an aftermarket gauge on it and it's reading the same thing, and I just thought about it before I rebuilt the motor I bought the oil pump and just put it in and the book didn't say anything about prime the pump so I just started the truck up.. could it cause that burnt up the oil pump or cause it to fail, not to mention it's like 70 degrees here and I imagine that the oil might be thinning out quicker.. I used 5w 30 like I recommended in the book..
Apr 10, 2014 at 10:03 AM
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JACOBANDNICKOLAS
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Since we now are sure the pressure is going to 0, the oil pump is now the prime suspect. You should have primed it first.
Apr 11, 2014 at 5:16 AM
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TRAVIS36701
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Yes but I have no idea how to prime it so I just pure a little bit of oil into the pump and turned the shaft a little.. but I've unplugged the crank sensor to send oil through out the motor and as high the gauge gotten up to was 40 psi that's just by spinning the motor over..
Apr 11, 2014 at 5:27 AM
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JACOBANDNICKOLAS
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Basically, to prime the pump, you just fill it with oil. I'm not sure I understand what you are saying. You get 40psi by spinning the motor?
Apr 11, 2014 at 5:33 AM
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TRAVIS36701
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I didn't fill the pump up beore putting it in.. Yes I unplugged the crank position sensor so I can spin the motor over without it cracking up and the highest the oil pressure gotten was up to 40 psi.. You think I should just get another oil pump and be sure to prime it before installing it or try priming the oil pump with a high speed drill ?
Apr 11, 2014 at 5:47 AM
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TRAVIS36701
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Or is it possible that air might be trapped in the oil system cause I did notice when the oil dropped when I used a aftermarket gauge that through out the line it'll have oil sitting in different spots with a air gap of two to three inches long apart from each other..
Apr 11, 2014 at 8:05 AM
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JACOBANDNICKOLAS
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I don't think it has anything to do with air. I have one last question before I recommend replacing the pump. What kind of oil filter is on the vehicle? Are you certain it is the correct one?
Apr 11, 2014 at 8:44 AM
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TRAVIS36701
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At first I used fram oil filter but now I'm using Purolator oil filter
Apr 11, 2014 at 9:01 AM
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JACOBANDNICKOLAS
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They are both good brands as long as they are the correct ones for the vehicle.
Apr 11, 2014 at 9:53 AM
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TRAVIS36701
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They're correct ones, the name brand oil pump I brought is melling but this time I'm thinking about going with sealed power. thanks for the help..
Apr 11, 2014 at 10:04 AM
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TRAVIS36701
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Ok I just found out my water pump is pumping while I accelerate the motor and causing the motor to over heat but the oil gauge was holding between 15 and 20 psi at idle and up to 60 at acceleration. so is it possible since it was over heating that cause make the oil thin out where it wouldn't pump and cause the motor to stall ?
Apr 11, 2014 at 4:43 PM
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TRAVIS36701
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Meant it isn't pumping while I accelerate and the sensor didn't say that it was running hot until I took the thermistat out to make sure it had planty of water and seen that there wasn't so I added water that's when it started saying it's running hot..
Apr 11, 2014 at 5:04 PM
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JACOBANDNICKOLAS
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It will cause the pressure to drop if it is overheating. However, all the way to 0 is questionable. I would repair the pump and try it. Maybe it will take care of the issue.
Apr 13, 2014 at 7:09 PM
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TRAVIS36701
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I've replaced the water pump it's holding 20 psi at warm idle and between 65 and 70 psi while driving.. I still have to get new radiator and cap cause my cap the rubber around it is dry rotting and falling into the radiator.. while I'm at it decided to put a engine oil cooler kit so it'll also knock down the heat of the oil..
Apr 14, 2014 at 4:39 AM
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JACOBANDNICKOLAS
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Everything is working correctly now? If so, that's great.
Apr 14, 2014 at 5:26 AM
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TRAVIS36701
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Yes it's running awesome but still running a little warm but that's only because the cap is bad and once in awhile I gets a small mist but believe that's just bad gas maybe..
Apr 14, 2014 at 5:32 AM
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TRAVIS36701
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Well I'm guessing it's a bad radiator cap cause when I cranked it up yesterday while it's cold I moved it about 15 foot to make sure the radiator had plenty of water I cut it off waited 10 minutes before taking the cap off it had a lot of pressure on the cap itself where it blew the cap off and water went everywhere all over the motor and the hood..
Apr 14, 2014 at 5:52 AM
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JACOBANDNICKOLAS
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Was the engine hot when that happened?
Apr 14, 2014 at 8:37 AM
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TRAVIS36701
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No it was warm but it wasn't hot, it was like it had a lot of air built up into the radiator cause I had to take a large pair of channel lock pliers to help turn it while I press down on the cap..
Apr 14, 2014 at 9:06 AM
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TRAVIS36701
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Not to mention when the water goes down seems like the water only flow through the top half of the radiator than it'll start flowing out of the radiator while the cap is off.. maybe the radiator is particularly clogged or either the cap is bad.. figure I've rebuilt the motor I should just go all the way and buy new radiator & cap
Apr 14, 2014 at 9:29 AM