I just put a LSX 376 B-15 in my '11 GMC Sierra. I'm running the oil pump that the LSX engine came with. I am running the oil pick up tube that came with my stock 6.2 in the truck. It had a orange O-ring so I got a brand new orange O-ring and placed it on the oil pick up tube. My oil pressure at ideal is probably around 25 psi and at WOT it still never makes it quite to 40 psi. My question is do I have an issue? Currently I still have the pressure relief valve in my oil pan and I've read that you can get some more PSI by plugging that valve off, but why did my stock 6.2 w/ relief valve idle around 35-40 and now this brand new LSX idles at 25 psi?? Just wondering if anyone has ever dealt with this before.

Thanks for any and all help or advice.

Josh

 

Different bearing clearances and oil temps could bring pressure down.

25psi isn't bad, still plenty of pressure for a motor at idle. I'd remove the relief because you really don't need it.

 

How do you feel about high pressure oil pumps? You get a lot of mixed feelings about them by reading different threads. Some people won't touch them and others love them. I'm about to put an F1A on my engine early in '17 so I would personally like to know I've got a little more oil pressure than 38 PSI.. Also plan on running a larger oil cooler.

 

Remvoing the relief seems to bump oil pressure well into the 50's and maybe even 60 at WOT.

 

What oil weight is recommended for the b15? 20psi isn't a bad idle pressure, but I would sure want my WOT past 40psi.... What's your cold startup oil psi? Not sure, but I wanna say that oil bypass doesn't even start bypassing oil until around 50-60psi? Could be sticking or something? Never know... Best thing to do is remove it and put a bolt in it. I gotta look around, but I believe the bolt size is m14x1.5

 

I attached a picture of the break in procedure per GM. They do not state the specific weight oil they just state that it has to meet the GM4718M. Mobil 1 is an oil that meets that standard. I can only assume that the standard oil for LS3's would be the best oil so I'm running 5W-30 mobile 1 w/ some Lucas break in oil additive.

Cold start up PSI is really close to 40 if not at 40 PSI.

Yeah I'm going to plug it but it's gonna be a pain In the butt!! Sense my truck is a 4wd I will either have to pull the engine again or drop the front diff - which is what I'm probably going to do. It's possible that it's sticking but it wasn't when I pulled it out and I cleaned it off really well before putting it back in. Yeah that is the correct thread call out. Dorman makes a drain plug that I'm going to pick up and put in the relief valves place.

I just wonder if I should put a high flow oil pump in while I'm there?

 

5 30 is thin. i like rotella 15-40.
you said pickup off the original 6.2 but what pan? it should be the same as where the pickup came from.
40psi past 4000 rpm is breaking an old rule of 10psi per 1000 rpm. i would be worried about that.

 

I'm using the stock L9H oil pan from my 1500 GMC sierra 4x4.
yeah I used the same O-ring that my stock truck was using so I doubt the o-ring is the issue unless I managed to pinch the o-ring when installing the pick up tube. I just talked to my tuner and says that the pick up tubes have a check valve in them. So before I put it on the dyno I'm going to replace that check valve and block off the safety valve located in the oil pan and see how that works. If still having oil pressure issues then its got to be the oil pump. The one I have in the truck is brand spanking new so I doubt that's the issue, but then again we are talking about me and my crappy luck.

 

My tuners text wasn't very clear. I talked to him later today and found out that He was talking about the relief valve located in the oil pan.

 

Anyone know the part number to the dorman plug used to replace the oil pressure relief valve?