What’s up guys! I’m new to this Forum, came on here for your feedback. I recently got a 2008 Chevy Silverado with the 4.8 in it. I am experiencing low oil pressure after the truck warms up. Starts off in the morning around 40-42 then as truck warms up, drops all the way to 10psi. Truck runs perfect though, No low oil pressure light or signal on the dash, cluster is just reading 10-12 psi as truck warms up. I have changed the oil and used Mobile 1 filter, even bumped the oil up to 10w 30 instead of 5w 30. Replaced oil sending unit and screen. Dropped oil pan and replaced pickup tube and O ring. What else can i do? Appreciate all the help!

 

Welcome to the forum. Moving to the Silverado section of the Forum where you'll get more views.

 

I don't see anything to worry about with your post. To increase the oil pressure with using a higher viscosity oil, you need to make the top end number (30) to a 40w. 5-40 or 10-40.

 

I put Rotella in it 15w 40 and nothing changed so i switched back to 10w 30. So i shouldn’t worry?

 

If your seeing 10-12 psig at warm idle, I'd not give it a thought.

 

Okay. Thanks so much! Truck is running fine and there is no i oil light on or anything. Kinda confusing. It’s like it drops as it warms up, but only 10-12 don’t go any further down. No ticks, knocks or anything. Just wanted somebody else’s opinion, i appreciate it!

 

Both of my GMT900 5.3L Tahoes ran around 10 psi at idle when warmed up. I would caution against using a heavier viscosity oil than what is called for because today's engines have a lot tighter tolerances and you run the risk of it not getting the proper oil film if it's too heavy.

 

Im just gonna leave the 10w 30 in it and see what happens! Lol, it eases my mind though knowing yours ran at 10psi at idle as well. Thanks for the help

 

You're welcome. I'm amazed at how thin the oil is that's recommended for today's modern engines. I have some that are 5W20. I remember that I always ran a heavier weight oil in my '68 GTO because I was the mistaken opinion that that would be better. Probably after I got a hundred thousand miles on it, it probably was better. Just wasn't a good idea in the early days.

 

How many miles on the motor?