This plug only give output pressure from the oil pump, not accurate to test actual pressure from oil filter to other parts. There an adapter bolt on to the oil cooler plug above the oil filter which allow you to hook up mechanical gauge to it, that will give you a true reading.
So the point your mechanical gauge is is pre oil filter. The pressure sensor is post oil filter. I had this exact issue. Changed the oil filter and poof right back to normal.
Interesting. As we both know, all the oil must pass through an LS oil filter as there is no "bypass" like on a small block Chevy (or 454) - and yes, the filter can certainly cause a pressure drop. What brand filter do you prefer ? I use Microgard (O'Rielly) as they are the same as a Mobil 1 filter. Also, AC Delco. I shy away from anything else only because I don't know the flow restriction.
Some LS do have an internal bypass located in the oil pan. I watched one video were the fitting cracked the pan and cause low oil pressure. I honestly have seen all sorts of different brands cause this issue. I personally just bought a bunch of premium guard filters as they are very well constructed. No leaf spring and they use holes in the centre tube. I can’t prove it but I think this new fad of using louvers in the centre tube is a bad thing.
@@jacobmartin1951 That's not a "filter bypass", that's a 50 psi (starts to open at 50 psi) relief valve that spills oil into the pan before the oil makes it's way back up to the engine. The filter is "full flow" 24/7. Unless you are referring to something different (something I haven't seen) . I'm all ears. Never to old to learn so fire away.
Hello I replaced my oil pump with a high volume oil pump replaced my pickup tube replaced my oil sending unit and filter gauge still says I have low oil pressure I hooked up an external oil pressure gauge and I had a cold start 80 lb of oil pressure warmed up to 210 running temperature idling at 59 lb if I have this kind of oil pressure why does my gauge in my vehicle say I have low oil pressure motor makes no noise no lifter taps nothing runs smooth is the pressure relief valve in my oil pan having an effect on my pressure at the gauge in the vehicle I have no idea at this any information at this point would be thanks.
I've seen this many times (where the gauge doesn't reflect actual oil pressure) and all I can assume is the gauge is bad, or something in the instrument cluster that feeds the gauge is not functioning correctly
@@mark_osborne thank you I was kind of leaning towards maybe it was my instrument panel on Monday I'm going to put in a conventional oil port off my oil cooler to get a better reading of my oil pressure other than right off the oil pump..
@Mark Osborne no lift required but removal of the accessory bracket makes life easy. Clogged oil filter can cause a discrepancy. I installed. Permanent mechanical gauge under the hood
Did you get it hot enough to where your inside gauge dropped to almost zero and check the manual pressure gauge to see if you were still above 20 psi? did you fix the problem?
I have 08 yukon denali 6.2 220,000mi on it it's a non afm dod engine. Im Having low oil pressure issue's, i change the pick up o ring clean pick up tube screen, changed the sensor and put a new filter. My pressure sits at 10psi hot idle and under a load sits at about 21psi tops. Cold start pressure is around 55psi is this normal??? My dash light has went off twice already once before I did all this work. Then just recently right before an oil change. Changed the oil and its now doing what I just stated. Did u think it could be the cluster gage????
thats pretty normal for the GM ls engine. another indication for the non DOD and AFM engines is if you have valve train noise. if you do when oil pressure goes to zero or just really low then you most likley have an oil pressure issue. i have a 2008 non DOD and non VVT 4.8 engine and i replaced pickup tube oring, timing chain, oil pump, new gaskets on oil pan and front and rear covers, and valley pan and new ac delco oil filter. I also have no screen under oil pressure sensor and i still get the oil light that comes on only at idle. the engine runs so quiet to. when engine is above 1000 rpm i get close to 40 psi. so even though GM LS engines are nice their oiling system is not so good!!
Did you get it hot enough where inside the truck gauge read almost zero and see what the manual gauge read? Was it still above 20 psi on the manual gauge?
