LS swap lost oil pressure

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iamtherealJayy

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Best way to clean the pan and pickup screen?
 

iamtherealJayy

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Here’s the filter, I’ve got it all back assembled about to refill with oil. Does the short/tall filter make a difference? I saw somewhere it did and I had the taller filter. I also noticed 08/22/05 on the inside of the oil pan, so the engine must be from 05? Just with an older ecu? I thought it was drive by wire by 05 lol
 

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iamtherealJayy

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And the results are in, I used an ACdelco PF61E filter and Quaker State 10w-30 oil(5qt) and one quart of Quaker 5w-30, prefilled the filter, installed, filled oil, fired engine and,
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No change, it took a second to build pressure and went to 15 psi, I never checked with a mechanical gauge but it builds pressure with rpm so I know the gauge is atleast somewhat working. And the oring was around same effort as changing the sensor behind intake. I don’t understand how it could run so quietly and smooth but have such low oil pressure. Should I go to a thicker oil or just live with it? Oil is about halfway up the hash marks. I need to know something within the next twelve hours because I’ve got an appointment to drop it off at an exhaust shop and regardless of how it gets there, it’s going to get exhaust.
 

Ricko1966

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Well I almost answered this on post 2 close, but somehow the number 10 got left out. It is there now.
 

iamtherealJayy

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@Ricko1966 do you have a tachometer recommendation that would directly work? My cheap Amazon tach doesn’t have a functional 4cyl setting. There’s a “switch” on the back but it doesn’t do anything since it’s not connected to anything on the inside.. and where’s the easiest accessible location to hook up a mechanical gauge?
 

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The filter does not look great to me. What are the particles in it? Paint, aluminum maybe? Normally, you will not find anything with the naked eye, other than what may have been introduced during a sloppy service or oil top up. Possibly mishandling from the previous owner or was the engine pulled from a wreck?
Since you have cleaned everything now, you have established yourself a new base line. If you are internally making debris, a major failure is more than likely imminent.
I normally wouldn't recommend a muffler shop for engine diagnostics, but checking oil pressure with a mechanical gauge is not very technical and a lot of muffler shops have guys capable. You may want to ask them if they have the resources to do so if you do not. The fluctuation in your gauge could be a flag and would be a concern for me.
 

iamtherealJayy

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The junk on the filter could be sludge? There was a little bit in the very bottom but other wise the engine was clean. I did get some paint inside of it from cutting the filter open. The oil was very black despise only having 100 miles on it. There was a slight metallic inside the filter but nothing major it didn’t look like glitter or anything just the occasional shiny flake.
Edit: the magnetic tip on the drain plug did have a small amount of buildup on it, I cleaned it before reinstallation
 

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With unknown hours on past service intervals, a bit of sludge would not be a big concern. It's the particles and fluctuating gauge that would for me.
As mentioned the pressure is not great but within spec. Aluminum and other bearing material will not stick to the magnet. The filter catches it before entering the main oil gallery.
Filters are cheep. Cut another open not too far down the road to see if you are making more. If it is clean, spin another on and carry on.
I would still look into getting the oil pressure checked mechanically. Your gauge could easily just be an electrical gremlin, but it sounds like you just moved it over from your last engine.
 

iamtherealJayy

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Yes, the gauge and sensor are from the prior 350, which actually did have oil issues. Pressure was worse than this one and the rings were shot etc, the shop that’s going to do my exhaust today does other work, he just so happens to have a tubing bender and welder so I’m having him do exhaust. I’ll bring up the oil pressure and see if he’s got the means of checking it while it’s on the lift.
 

Ricko1966

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Post #20 jayy you should let one of the guys more familiar with the that swap answer that. I haven't done one.
 

iamtherealJayy

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I asked the shop if he had a way of checking it and he said it wouldn’t be any issue hooking up a mechanical gauge, I’ll have results at the end of the day hopefully. And an exhaust of course lol
 

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Oil black in 100 miles tells me something is drastically wrong.
 

iamtherealJayy

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@Ricko1966 @peats @Buck69
Got the truck back from exhaust shop, truck fired right up at his place 0 oil pressure, no engine noises at all, backed out in the road took off averaged 20 at 55mph and got over 40 when going through the gears, 0 at idle. What gives? He said he hooked a mechanical gauge on it and it showed 20 at idle(not hot) I don’t know where he hooked to I forgot to ask
 

Ricko1966

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So you show zero at idle his gauge says 20 at idle that's the way I understand this if that's the case put a different gauge of your own on it to verify his readings I think you have a bad gauge,or a bad sender.
 

iamtherealJayy

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Then again I don’t know where he hooked his gauge, he could’ve hooked directly to the pump, or not done it at all, I’ll never know. But you cannot make me believe the truck has 0 oil pressure and such delayed oil pressure with rpm and sounds so quiet and smooth
 

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