Hello, a week or so I ago I posted this on here: https://www.reddit.com/r/ChevyTrucks/s/XM0RocsiPI.
In regard to my oil pressure, I also have a lazy/wearing AFM lifter on cylinder 4 or 6. I have AFM disabled with an OBII chip, and the guy I bought the truck from had the top end redone. The shop redid 1, 3, 5, 7 twice after a lifter failed but only did 2, 4, 6, 8 side once. My motor mounts are pretty worn (visually seen after doing throttle in D and R with brake applied test, engine does indeed shift back and forth either way). I’m figuring the motor mounts are exaggerating an already slight rough idle that could be partially due to the lifter. No codes or anything, new plugs, air filter, and cleaned MAF and throttle body, same coil packs and wires but they seem fine. Just wanted some feedback here.
Here are my oil pressure numbers. I run Mobil 1 Full Synthetic High Mileage and ACDelco PF48 (as I heard it’s great and helps with oil pressure, which it did, used to run WIX 57060XP, but with 4k intervals, the ACDelco works just fine for me). Attached is a video with cold and hot idle, changes halfway through video and hot is obviously second portion with the lifter tick.
- 42-50 psi cold start (engine is quiet, just normal GM noise)
- 18–22 psi hot idle (slight lifter tick present when fully hot)
- 25–40 psi while cruising it rarely gets anywhere near 60 psi.
I’ve read a lot about possible causes: think I may just run it a while with all these conditions before dropping pan and doing o ring as it’s such a pain on it since I have 4x4
- Oil pressure sensor/screen (already replaced)
- Oil pickup tube O-ring
- Cam bearings
- Oil pump