Oil pressure issues

2008 5.3 flex fuel afm 197,500 miles.

I can only get maybe 1,500 miles on an oil change before check engine light comes on for low oil pressure detected. Changed sensor the first time I got the code, screen was clean but replaced anyway. Also changed oil at the same time. Has always used Oil, have to add a quart every 1500 also. It appears I have a leak where the oil pan attaches. Have been using Valvoline high mileage synthetic mix since 100k. With fresh oil change 30 psi at idle, 40+ at highway speeds. As oil gets old drops to less than 20 cold, and 20 at warm idle, 30 or less at 60 mph. Any ideas?

That is low, if this can be verified with a gage attached to the sender port, then I would consider a new oil pump set up, I believe this was somewhat common on those engines, do some online research first. High quality filter? Not a severe leak? Keep in mind any internal bearing wear can cause all these conditions.

2008 5.3 flex fuel afm 197,500 miles.

I can only get maybe 1,500 miles on an oil change before check engine light comes on for low oil pressure detected. Changed sensor the first time I got the code, screen was clean but replaced anyway. Also changed oil at the same time. Has always used Oil, have to add a quart every 1500 also. It appears I have a leak where the oil pan attaches. Have been using Valvoline high mileage synthetic mix since 100k. With fresh oil change 30 psi at idle, 40+ at highway speeds. As oil gets old drops to less than 20 cold, and 20 at warm idle, 30 or less at 60 mph. Any ideas?

Has this truck had the updated valve cover from GM? What about the AFM deflector shield in the oil pan over the valve itself? There are bulletins about oil consumption on these engines back to like 07 up till 10 or 11. Very common. I would take your vin into a GM dealer service dept and have them run it to see if any of this was done on warranty. I did many of these when I worked for GM from 07-12. Also there were updated oil caps there were vented to help reduce pressure on the pcv system. Also from the sounds of it the oil pan gasket is leaking, but I'm wondering that if you might have bigger issues if any of this has been done.

Have owned this truck since new. I replaced with new valve cover, but did not do deflector. I guess i just dont understand why oil and filter change fixes the problem temporarily. Have used same oil filters for life of truck so I don't know how that could be the issue. Oil changes every 5000 miles until this issue started, then I started doing them more often. Moot point now except to help others. Traded it in last night while it had fresh oil and no check engine light.