07 Denali oil pressure talk

[West 1]

An oil pump can last a very long time. I only changed mine because I thought the Melling offered more flow. Finding metal in the pan is. Never a good sign.

 

[Geotrash]

If I were you I’d have a local Indi or diesel mechanic keep his eyes out for a GM 2500 or 3500 that’s wrecked with a good 6.0L L96. They have alum block, iron heads, runs on reg fuel and later versions on e85 too.

Just a quick note here to make sure the record is right for future readers, the L96 has an iron block. I own one. But I agree with you that it's a great replacement for an L92. Runs great on regular gas and built hell for stout.

L96 6.0L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 6.0L L96 LS engine.

www.onallcylinders.com

 

[Marky Dissod]

For the vast majority of people who are thinking about replacing their 5.3L with a 6.2L,
but hope to get away with using 87 octane, a 6.0L would likely be a superior option to a 6.2L.

 

[petethepug]

Heheheee, got that one transposed. Aluminium block, iron heads. Couldn’t båstardize a motor anymore than doing that to it.

 

[West 1]

I just bought a 2008 Yukon Denali with the 6.2L, it runs fine and has no odd noises but cold start it has 40+ pounds of oil pressure and it quickly drops to 20 at hot idle. 40 psi while drivng, not at idle.
It had an oil pan leak so I decided to go ahead and pull the pan this week and fix the leak and also address the oil pressure.

Pan off, the oil pick up tube had to be pulled out, did not fall out from a dead O ring. I had purchesd Mahle O rings for the pick up tube because they were available quickly local. I prefer the red Fel Pro Oring for these. I have done more than a dozen in the past couple years using the Fel Pro so I know how it fits..

On install the Mahle red Oring was a little loose? Not bad loose but looser than I expected on instqall. It had some resistance but I am used to having to push pretty hard to pop the pick up back in with a new Fel Pro O ring ( orange or Red not sure). I needed this back together so I doubled up on the Mahle Oring. 2 of them are now installed. With 2 orings in there it went in tight and tightened up normally??? I do not like going away from stock design but this is now tight, there was room for the double Oring so I did it. These O rings just seal vacuum to help the pump pick up the oil, no pressure so I think it will work just fine.

Time will tell but I think this will solve the loose O ring issue. While in there I pulled the Oil Pump Relief spring and added a shim to add a little oil pressure, call me silly but I like it when I have 60 psi on the highway. Also installed a new secondary oil by pass valve in the oil pan, GM part. ( this one is not necessary on this engine since it does not have AFM, the secondary valve limits oil pressure to 65 PSI max on these engines. Above 65 PSI max can damage AFM lifters so that is the reason GM added this secondary relief valve.

Should know in a day or so how the hot idle oil pressure is on this Denali, 6.2L with 140,000 miles.

I am going bumper to bumper doing full maintenance to make it a reliable truck. New Tires, All new hoses, Brake system flush, new oil in PS, front diff, rear diff, transfer case, transmission and the engine.
I expect the oil pressure will be solid with 30 psi + hot.

 

[donjetman]

Here's my experience for our 07 6.2L L92 that has always had normal/healthy oil pressure = 50 psi cold idle, 15 psi hot idle, 35 psi hot at hwy speeds:

I recently removed an aging Felpro# 72401 o-ring that I had installed 5+ yrs ago and installed a new Mahle# B32790 o-ring. Both fit fine. No issue with either.
https://www.tahoeyukonforum.com/threads/valley-cover-crank-pulley-etc.149036/#post-1886005

I did install a 2nd bolt this last time I was in the pan.
https://www.tahoeyukonforum.com/thr...sket-pickup-o-ring.146226/page-2#post-1948337

In 2018 I installed the relief valve "deflector" GM# 12639759 per the GM TSB# 10-06-01-008M:
https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf
along w/the updated ds valve cover and piston/combustion chamber soak of all 8 cylinders.

I still have a catch can installed since 2018 and it no longer catches much oil (2 oz) between oil changes since doing the TSB in 2018: https://www.tahoeyukonforum.com/threads/preferred-catch-can.106012/page-3#post-1314815

 

[West 1]

That is funny, I considered adding the second bolt on the oil pump, had not seen that done before.

On the pick up tube the O ring does not crush into place it just rides in there to seal air leaks. Not like a high pressure Oil seal with hydraulic connections.
There was room for a second O ring so I tried it. If It works like I think it should it adds one barrier to the pick up tube failing. I will test fire it before assembling the rest of the truck just in case I need to pull the pan and correct it.

 

[rdezs]

I use this one on every LS engine build.

Z Whip LS Oil Pump Pickup Tube Girdle Pipe Hold Down Brace Support Billet Bracket MADE IN THE USA Compatible with GM Chevy LS Series Engines LSX LS1 LS3 LS2 LQ4 LS6 LQ9 5.3L 6.0L 6.2L https://a.co/d/bEnT8Eg

 

[rdezs]

 

[donjetman]

I put one in my cart for future use.
I currently own 3 vehicles with LS engines.

 

[rdezs]

It's one of those things where there's a threaded hole for the second bolt.... But I imagine GM has saved millions of dollars leaving that one bolt out on all the lS engines they built, LOL. All the aftermarket pumps have the two threaded holes as well. I'm sure it came down to some pencil pusher interrogating an engineer as to if it could work with just one bolt! And they really thought we wouldn't notice? OMG

 

[rdezs]

While GM has moved completely away from fiber gaskets, as pretty much everyone has.... If they are just designed it with a flange on the pickup tube to mate a flat surface on the pump, with a fiber gasket in between, it sure would have saved a lot of engines!

 

[steiny93]

so I doubled up on the Mahle Oring. 2 of them are now installed

don't do this, same reason you don't double up on oil filter gaskets, 2 will leak

 

[Charlie207]

I put one in my cart for future use.
I currently own 3 vehicles with LS engines.

I added one like that when I rebuilt my engine. There's already a drilled and tapped bolt hole there, unused. Might as well apply extra preventative protection.

 

[SpareParts]

don't do this, same reason you don't double up on oil filter gaskets, 2 will leak

Apples to oranges comparison.
Doubleing up on a O ring in this situation Can't hurt.
Oil filter is a entirly different situation.

 

[steiny93]

Apples to oranges comparison.
Doubleing up on a O ring in this situation Can't hurt.
Oil filter is a entirly different situation.

i disagree, here is why

a single o ring fills the void between the metal surfaces, sealing happens

since the o ring(s) being used are the wrong size they are not sealing between the metal surfaces as such the two o rings need to seal between themselves. The o ring to o ring connection will leak.

this is the same situation as dual filter gasket, leak will occur between the gasket/o ring connection

 

[West 1]

I would agree in o rings under pressure, that is not the case in the pick up tube, in the pick up tube the O rings are there to fill a void and seal against air under vacuum. Many applications use double O rings in similar situations. I will report back after fire up. I assume it will work fine but time will certainly tell.

 

[rdezs]

Never tried it, but off the top of my head I don't see a problem. The place it seals is between the pickup tube and the outer bore of the hole it slides into. The face of the o-ring isn't really compressed against anything. I'll have to measure the depth on an oil pump when I get home, in relation to the flange on the pickup tube. I'm thinking there's room without compressing the o-rings.... Which even if it did, could only help. I'll do some measurements with photos when I get home.

 

[j91z28d1]

i disagree, here is why

a single o ring fills the void between the metal surfaces, sealing happens

since the o ring(s) being used are the wrong size they are not sealing between the metal surfaces as such the two o rings need to seal between themselves. The o ring to o ring connection will leak.

this is the same situation as dual filter gasket, leak will occur between the gasket/o ring connection

2 pieces of rubber like o rings seal very well against themselves under compression. the reason the double gasket oil filter leaks is not because of rubber to rubber seal, there's no support on the outside of the top gasket and pressure blows it out. if there was a metal support ring around the outside, it would he fine.

 

[West 1]

Got it back together today, fired it up. Oil Pressure picked up instantly even though I did not prime the pump. At full temp for almost an. Hour Hot Oil pressure at idle is 40 psi, at 2500 it is 55 psi. No leaks so far so all is looking good. Prior to this OP at idle was dropping to 20 PSI. I know that is plenty at idle but I don’t like low Oil Pressure.,
In this application I have zero concern about the 2 Orings. If one fails the other is there as back up.

I know the suspension alert is on. I am working to bring this truck back to life. I have a new air pump to install and then figure out if it needs new shocks also. Replaced the rear lift gate actuator today, easy job and now the gate works as it should, also installed a new rear window button so it can be opened normally. More work to do but at least Oil Pressure is golden now.