6.2 L86 Oil Pump Replacement or Mod?

[super_kev]

Hey folks, I've got a 2016 Denali with the 6.2 L86, and I will be doing a TSP AFM/DOD deletion in the future, but currently the DOD is tuned off via HPT. However, this past road trip of 600-700 miles, I noticed the oil pressure drop to 25 or so at idle when the engine is warmed up. The engine was replaced with a new crate engine in the past 25K miles by GM under warranty as the original one went bang around 100K (previous owner, I'm not sure of the symptoms). I do not like that oil pressure is 25 or so, and so I was curious what ya'll use for replacement oil pumps to get it up to 45-60 like it should be? I also stumbled across the washer/oil pump mod - any of you done this to the stock pump?

 

[Joseph Garcia]

Hot idle oil pressure of 25+ psi on these trucks is normal, and I would not be concerned until it were to drop to 20 or below. But, the pressure should rise dramatically as the rpms rise above idle. I have a Melling 10355 HP/HV oil pump, and right in the instructions, regardless of the spring that you select (3 spring options, with the +10 psi spring already installed in it upon arrival), it tells you to expect a hot idle oil pressure of around 25 psi.

The oil pan oil pressure relief valve in the video picture can (and should) be deleted, if you have the AFM delete installed (either by tune or hardware), as it is no longer needed, and is a failure point over time.

 

[super_kev]

25psi is normal? Perhaps that's why these things grenade over time (as well as the DOD lifter failure) as that's stupid low - and coupled with the thin factory requested oil vs. something like a 10-40, I don't think that's a good idea. A family member has a '98 suburban with 440K on the original engine - my goal is to bulletproof this one to be able to get to that mileage, and the fact that most of AFM/DOD engines fail within 100-150K miles isn't a good omen.

 

[SpareParts]

All about bearing clearance.

 

[West 1]

I have not seen that chart showing clearance and recommendations before. I think I like it.

Federal Mogul used to print a chart that showed how much oil spilled as the clearances were increased but it was from the 60's and all oil back then was single viscosity.
The old FM chart showed oil spillage change from .002 clearances to .0035 clearances was an increase of about 10x as I recall. If I run across that old chart I will post it.

To the OP, I have used the washer trick to increase oil pressure on 2 engines. It works to help the pressure above say 1500 rpm but did not change pressure at idle. I think you need the high volume pump to get the pressure at idle to increase.

 

[super_kev]

So I called TSP, and asked them and they said that there is a solenoid that controls the oil pressure and you can unplug it, but it'll send an error code light, though unplugging it will boost oil pressure as the solenoid dumps oil at idle. The tech guy said all gen V blocks have low idle oil pressure. Stumbled across this interesting article. What are the bearing clearances on the L86 6.2?

Bearing Clearances - Engines

Choose the right engine bearing clearances and oil viscosity for optimal performance. Synthetic oils excel in racing applications.

www.enginebuildermag.com

 

[Marky Dissod]

What are the bearing clearances on the L86 6.2L?

Also, what if any are the clearance differences between the L86/L87, vs the LT1?
'cause there are WAY too many of you who don't realize that the L86/L87 is very close to a clone of the LT1, yet L86/L87 require 0w20 or else.