L92 6.2 Issues and Fixes for the incredulous NOOB

[MontanaBoy]

Hey Crew, I did it. I got shiney wheel goggles on and got so excited about a good deal on a nice truck that i overlooked even the most basic stuff. After a week of driving my "Nused" 2007 Denali I decided to glance at the oil pressure gauge. I'm an idiot. No, its not just a bad sending unit. Perfect symptoms, it Starts up with a lifter clatter cold, builds 40 psi of oil pressure drops to 20 as it warms (oil thinning) and settles in around 8 at idle. it still has a slight lifter tick around 2000rpm at operating temp. (still maybe 20psi?)

What i am looking for is L92 Specific Common problems and their associated confirmed fixes. The L92 is a 6.2 WITHOUT DOD or AFM. I am under the impression it does in fact have VVT? from the reading i've done thus far i am trying to sort out the following potential problems...

1 oil filter (proven brands/Numbers?)
2 oil sending unit screen
3 Oil pump pickup tube o-ring
4 oil pump
5 oil pressure bypass (in Pan?)
6 oil pump pressure regulator (in Pump?)
7 camshaft bearings/Cam shaft
8 Lifters
9 valve cover/PCV? (5.3 only?)
10 Oil Bypass shield? (AFM only?)
11 High Pressure, High Volume, or stock oil pump?
12 does anyone make a quality upgraded motor mount?
13 VVT Actuator etc etc
I know i can buy the pump the gaskets and all the jazz for a few hundred bucks and just dive right in but it has been unclear the more i read as to which of these directly apply to the L92 6.2 the is found in My 2007 AWD GMC Denali. I'm quite fit to do all the work but im just wondering what im getting into and id like to not waste my time fixing stuff that doesnt need it.

Thanks for humoring the noobie, any and all help is appreciated. As you can imagine the only threads i read before buying the truck were about how rad it is going to be after getting it tuned by "Lew" or blackbear...

 

[FrankU]

Welcome !

I'd start with the basic's, putting a known good mechanical gauge on the engine. Then a good oil and filter change. How many miles are on the engine ?

 

[MontanaBoy]

Welcome !

I'd start with the basic's, putting a known good mechanical gauge on the engine. Then a good oil and filter change. How many miles are on the engine ?

Yeah I'll be getting those things done this week. Engine has 150k.

 

[MontanaBoy]

Did the oil change today. Wix XP filter. compared it to the regular wix and the bypass spring (coil) seems to be even better than the regular wix along with a better filter element. I used Mobil 1 full syn 10w30.
Oil pressure is now bottoming just under 20psi at idle and close to 40 above 2000rpm. I wouldn't be surprised to still find the failed pickup tube o-ring.
Old filter removed was a Napa Pro Select which I'm assuming is Junk. Hard to say now whether the filter is to blame or if the thicker oil is the result of higher pressure. I guess next change I'll go back to 5-30 and see what it does. Still have a consistent noticeable low toned clatter even at operating temperature.

 

[FrankU]

Is it possible that the clatter could be the injectors ? Won't be the first time that's been the culprit.

 

[MontanaBoy]

Is it possible that the clatter could be the injectors ? Won't be the first time that's been the culprit.

Are you referring to the normal ticking/clicking of normal injector operation or is there a specific failure associated with the injectors that causes and internal engine noise? The noise I have I would normally associate with valve train or piston slap. It can lightly be heard from in the cab driving at city speeds with the windows up.

 

[FrankU]

Piston slap was common when cold with the earlier engines , and harmless too. The slap noise quiets down a bit when hot.

Was the oil really dirty when it was drained ?

These LS engines take lot's of abuse and neglect and keep on running.

 

[t.stimpson]

yeah my 2009 is very noisy when cold but goes away in just a few minutes. my oil pressure is usually around 30-40

 

[kctyler]

My 07 6.2 makes noise too. Always on start up, then when it gets warm it shuts up. People say "normal"....haha, its almost embarrassing sometimes.

Sent from my LG-H811 using Tapatalk

 

[JML07denali]

I have a 07 6.2 as well. Same issue here sounds like a diesel in the morning after the engine warms up it goes away. My oil pressure at idle is about 12psi and jumps up to over 40 when driving I think I might have a blown out o-ring on the oil sender tube. Other than that truck runs like a champ!

 

[kctyler]

Mine is loud inside, can hardly hear it outside. I took a co worker home the other day. He asked, "why does this sound like a diesel".

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[JML07denali]

Mine is loud inside, can hardly hear it outside. I took a co worker home the other day. He asked, "why does this sound like a diesel".

Sent from my LG-H811 using Tapatalk

Haha I get it all the time. I now just say I have a duramax in it.

 

[MontanaBoy]

Oil wasn't bad at all but was from the previous owner and I dont have a clue what it was. I think it was cheap conventional to go along with the cheap generic filter.
Yeah I'm pretty familiar with the typical cold engine piston slap but I do have a noticeable noise at operating temp. How about any of the rest of the stuff? Cam and lifters common on this motor?

 

[tomustang]

What gas are you giving it? Do 89, if you are then try 91/93

 

[kctyler]

I have tried different oil filters, Lucas oil additive, Marvels, and I always run 91 with Mobil 1 full synthetic 5w30. Nothing I do makes any difference at all. Until the engine warms up, that damn tick is there. I did however notice with a K&N oil filter my oil pressure is more consistent.

 

[BlackOh7on22s]

Just an FYI, Napa oil filters are actually made by WIX filters. The oil pressure switches are known to be faulty also on these

 

[MrMyers]

From Summit Racing :

Intro to the L92, L9H, and L94​

LS Family: Gen. 4, 6.2L, Aluminum Block, Truck Engines​

L92​

The L92 was introduced in 2007 for GM luxury pickups and SUVs. It was the first 6.2L LS truck engine. It was commonly known as the Vortec 6200.

L9H​

The L9H replaced the L92 in 2009. It was upgraded with Flex Fuel capability. The L9H was also known as the Vortec 6200. It was available until 2013.

L94​

The L94 was introduced in 2010. It was a premium option in the Escalade and Yukon SUVs until 2014. The L94 added Active Fuel Managment (AFM) technology for better gas mileage. It was also known as the Vortec 6200.
For specific details about these engines, please follow the links below:

• Chevy L92 Engine Specs
• Chevy L9H Engine Specs
• Chevy L94 Engine Specs
• Upgrading the L92, L9H, and L94 Engines

Benefits​

These engines are truck versions of the high performance LS3. The stock engines all make over 400 hp.
The engine blocks have the same casting number as the LS3 and L99. They share a 4.065 in. bore, Variable Valve Timing (VVT) and rectangle port heads. The blocks also have the internal oil passages for AFM.
The cylinder heads are dimensionally the same as the LS3. However, they have different casting numbers. They used different valves, camshaft, intake manifold, injectors, pistons, etc. This helped them make more Torque lower in the rpm range. However, it did limit the top-end Horsepower.
These engines can be bored and stroked up to 427 c.i.d. (7.0L). With upgraded internals, they can handle around 1,000 hp.

What's the difference?​

The easiest way to tell the difference is to check the 8th digit of the VIN code.

• Follow this link to Identify an LS Engine by VIN.

The difference between these engines is the special technology they used.

• For fuel compatibility, pull the injectors.
• • Standard injectors have 2 holes in the end of the nozzle.
  • Flex Fuel injectors have 4 holes in the end of the nozzle.
• Follow the links provided above to identify AFM and VVT engines.

RPO Code	AFM	VVT	Flex Fuel
L92	No	Yes	No
L9H	No	Yes	Yes
L94	Yes	Yes	Yes

After talking to a service tech at my GM dealer, he confirmed that the only difference between the L92 and L9H is the injectors. He also stated that when running E85 in the flex capable motors, they run hotter, and to me that means shortening the potential service life of the engine. But upgrading the injectors to the 4 nozzle type and reprogramming the ECM for those injectors, and running 87 octane fuel with the GM specified AC Delco oil filter might help with the noise at temperature. Otherwise, valve jobs on both banks will get it gone.

 

[rdezs]

Lol....thank you Mr Myers. The guys been waiting for someone to respond to that post since 2016. I'm on the edge of my seat wondering if he's going to respond 9 years later ;-)