On my 2008 suburban 5.3 flex fuel, I had an issue with low oil pressure and
after changing filter and oil pressure went back to normal. Now I have 450
miles since change and pressure is slowly dropping now at 30psi at idle,
when changed it was 40psi at hot idle. Is there anything to cure this issue
On 2007 on up GM put a fine screen under the oil pressure sending unit. The screen of course gets plugged up and needs to be fished out and cleaned. I would advise replacing the oil pressure sending unit at the same time. When doing this you could check the oil pressure with a mechanical gauge to verify what you are seeing or not seeing on the dashboard gauge.
Just before this last oil change about 450 miles ago the dealer replaced the sending unit and screen and my pressure did not change. That's when I changed the oil and filter which made it normal for several hundred miles, then it slowly started to drop again
One possibility may be the oil pump itself. I have heard on the 5.3L of some oil pressure issues, and replacing the oil pump took care of them. Also the right oil needs to be used in motors these days, but I see the Dealer serviced it, so probably not your case on that.
yeah and when I switched it I used 5w-30 mobil1
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