I have a 2006 1500 Silverado w/ 189000 miles. Since about 150k I have had very low oil pressure on start up. Low Oil Pressure alert going off. Once I drive for about 20 min and get everything warmed up my oil pressure holds normal with no drop at all. This is only an idle oil pressure problem. If I take off and drive it holds at about 40 lbs....but when I stop and idle it goes back down. Or I can just idle at a higher rpm and it holds. I did use vmax 10/30 and just switched to penzoil high mileage. It seems to not be near as bad with the new oil. It is 10/30 as well. It does not matter if it is summer or winter when doing this, it just does not take near as long in the summer time to stop setting off the Low Oil Pressure alert. Any suggestions? One other thing, If I am sitting on an incline it does it worse. If the truck is declined it does not do it as bad. And this is when oil levels are prefect, so I know its not a low oil situation.
Low Oil Pressure on Start up on 2006 Chevrolet Silverado 1500
by jodybro1234 in Birmingham, AL on December 11, 2011
ANSWER by PARTS GUY , December 11, 2011
You most likely need to remove oil pan and clean or replace oil pump pickup tube/screen. You need to hook up a mechanical direct read oil pressure gage to see real time oil pressure. Read this info. There's a TSB concerning this problem. Tests/Procedures: 1. Inspect the oil pump. 2. Check the o-ring for the pick up tube. GM has a TSB #02-06-01-038 addressing this o-ring. 3. Inspect the cam bearing area for signs of a spun bearing. Tech Tips: In this instance, the engine had 60,000 miles on it and the o-ring appeared to be OK (no cuts or tears and it was soft). Replaced the o-ring and now the engine has good oil pressure.