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Discussion Starter · #1 ·
So I'm sitting in a McDonalds drive-thru and the oil gauge on the Atari dash hawk goes to no bars in drive and one bar in neutral.since my engine work that is in my sig, i have put about seven hundred miles on the engine and the oil pressure atty a standstill is usually two to three bars. What is going on here?? Could the new oil pump or Underdrive pulley be to blame? The car's oil pressure is fine at road speed, only at a standstill does it get low. Checked the oil which was changed about four hundred miles ago and it seemed fine, good color and level.
 

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Pulley has zero to do with oil pressure on a wet sump system. If you put a new melling pump on and for sure know the oil ring on the pickup tube was good and not pinched then I would check the pressure sending unit.
 

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Discussion Starter · #4 ·
How would you tell if the pressure sending unit is good or not?
 

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Quit relying on the Atari gauge and put a quality gauge on it. What weight oil did you put in it? What filter?
 

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Discussion Starter · #6 ·
Pennzoil platinum 5W30 with a Fram filter.
 

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I had this happen in my '57 Olds one day in traffic. The oil gauge went to zero unless I was on the gas and there was nowhere I could go or even pull off. I kept the RPMs up until traffic cleared (almost an hour) and when I got to work I put a gauge on it and the pressure was fine. So I suppose it is possible for a sending unit to stop reading under a certain pressure.
 

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Discussion Starter · #9 · (Edited)
I started it up this morning and let it run for ten minutes and the pressure was fine, had five bars the whole time. So, i took it out for a fifteen minute drive. It seemed like once the oil got warmed up and circulated, that oil pressure would drop back to two to three bars at idle. Again, at any other throttle position the oil pressure was fine. At highway speeds, on cruise control, the oil pressure stayed at 5 bars with no fluctuations. When I'm slowing down below fifty it will go to four bars. If i go below 30 it will go to three bars. Now all that is coasting down with no throttle added. If I have my foot on the throttle going any speed then i have four to five bars. I will be getting a quality gauge installed this week.
 

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Discussion Starter · #10 ·
So i got to looking around the engine bay and noticed the pcv on the valley cover that came with the dod delete kit has nothing attached to it. It is just a metal tube sitting there in the open. That is how it came back to me from the shop. I'm about to buy an oil catch can so it will attach there. Would that remedy my oil pressure problem?
 

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Discussion Starter · #12 ·
Hmm okay. As you can probably tell, I don't have very much knowledge of engines, but I'm trying to learn. If my car came from the engine shop, with them completely rebuilding the engine pretty much, other than this pressure sending unit being the culprit... What could be causing this? Could it, in any way, be normal after a compete rotating assembly replacement and DOD delete, cam swap and ported oil pump? Also, idk if it matters or if it's normal, but on the battery gauge when I'm driving reads at the 15 volt level. The only reason i had any engine work done is because when i was driving last year merging onto a highway the oil pressure went to zero and got a CEL. I stopped turned off the car and checked the oil level and it was good. Restarted the car and the oil pressure was good. Started driving again and after awhile it went back to zero and another CEL while driving. Again, i stopped and turned off the car then restarted it and the oil pressure was good... Then i heard a snap and then tap tap tap in sync with the RPMs. Turned out i had spun 2 bearings and messed up my crankshaft. Now, i don't have any CEL or weird noises coming from my engine, just lower oil pressure than i remember having when i was stock.
 

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Did they replace all bearings and the crank? Did they clean the pick-up screen and oil pump? Liable to have chucks of metal plugging the screen up.


Causes of low oil pressure (assuming switch is good):


1. Too thin oil weight
2. Restrictive filter
3. Faulty oil pump
4. Too much bearing clearance
 

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Discussion Starter · #14 ·
To answer some of your questions. They replaced all bearings and got a new crank, rods and piston heads all forged. They dipped and vated my block and made room for the stroker. I got a new ported LS6 oil pump from Texas speed. Idk about the pick up screen... The break in oil they used was 15W40 which i ran for about 500 miles then changed to 5W30. I'm about to change my oil again this week so i can change filters.
 

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Discussion Starter · #15 ·
The CEL i got before it went into the shop was P0521 (EOP sensor performance) and I'm guessing they didn't fix that.
 

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Discussion Starter · #16 ·
Can you help me identify a disconnected plug? It it's in the same harness as the O2 sensor and oil pressure sending unit. It is a male connector with five Ports. Idk where it connects to. I just found it behind the driver side of the intake manifold.
 

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Discussion Starter · #17 ·
 

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Discussion Starter · #19 ·
I'm on my phone right now. The picture is in my "garage" on this website under three album "engine"
 

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The CEL i got before it went into the shop was P0521 (EOP sensor performance) and I'm guessing they didn't fix that.
Well you should have mentioned that sooner. That is a code for signal performance on the engine oil pressure switch circuit. Could be a sensor, wiring, or the ECM. I would say since the gauge is working normally, the switch isn't working properly once the pressure drops a little at idle.
 
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