2009 GMC Sierra 5.3 LH6 alum block

Dnt · January 10, 2014

I looked through some threads and could not find the answer I apologize if this has already been resolved and please send me to that thread. I have a 2009 GMC crew cab 4x4 with the Gen IV 5.3 LH6 aluminum block and heads. I bought the truck in 2011 with approx 27k on the odometer. Soon after I bought it I started noticing that I was having to add oil between changes. I am using mobile1 5w 30 I now have 86k on the truck and it is a awesome ride and I really do like it but apparently the oil usage has started fouling out the spark plugs. I am guessing here but I think it might be around 1 quart per 2k miles could be more but defintley not less. Last week the Truck started missing pretty badly and then the check engine light was blinking and the truck went into what I call Limp Mode plus the traction control and stabiltrac system light on the dash came on. When I got home I checked the codes and it was P0301 which indicates cyl 1 misfire. I pulled the #1 cyl plug and it was covered in black gunk and completely fouled. I bought a new one (the irridium tipped plugs are over 7 bucks a piece) and replaced it and it is running OK but now that I am really listening and paying attention to it and it seems to have a fairly rough idle and a ticking noise especially on cold startups. Now after doing some research I see a lot of owners from 2007 to 2011 of the 5.3 engine are complaining about oil usage and some mention fouled spark plugs. I see a TSB for changing out the drivers side valve cover and adding a AFM discharge shield and doing a cylinder cleaning plus some have had their pistons and rings replaced? Apparently the work has only been partially successful and I would really like to know WHAT IS THE REAL ISSUE WITH THESE ENGINES in these year models. I do not like the idea of having my engine torn down especially if they are only guessing!! Could it be a AFM problem or maybe lifters or camshaft or something as simple as the PCV baffle in the valve cover? What has been your experience with this. I am all ears.

Btuggle88 · January 10, 2014

I read something on here, can't remember where, but it has to do with the AFM and the cylinders that shut down while its in V4 mode and the rings getting gummed up, but I'm not a mechanic but I'll talk to a friend of mine and see if he knows for sure

Doug_Scott · January 10, 2014

Take a look at the intake runner for cylinder one. Are there any vacuum lines on the intake runner, or close to that runner? Oil is getting into cylinder somehow. Some have put a oil trap on the pcv line. This trap will trap the oil that is suspended in the crankcase fumes being pulled into the intake via pcv line and valve. You may want to try adding that device into the pcv system.

I would try pulling all the plugs and check their condition. GM recommends changing plugs at 100,000km don't they?

Dnt · January 11, 2014

Thanks for the replys I have an appointment at my local GMC dealership service department Saturday morning at 7:00 a.m. so we will see what they say. I am not sure if the warranty will cover repairs or not. I think it may have a 5yr 100k Powertrain Warranty. Did some more research today and it is really hard to say how common the problem is but it is obviously a problem at some level. I know it is FOR ME!!! And yes the Irridium tipped spark plugs are recommended to be changed at 100k miles. I might just sneak a peek at some 2014 Sierras while I am there. Hopefully they have all these problems behind them now (probably have some new ones haha)

Dnt · January 12, 2014

OK dealer says intake has oil in it and they will change out the drivers side valve cover apparently it is a PCV free system it uses a interior baffle inside the valve cover instead of a valve. The new cover is redesigned to prevent the line to the intake picking up excessive oil . Also have a rear main seal leak so they are going to replace that. Will take 2 or 3 days so I told them i would be back next Saturday to pick it up. Got a nice Buick Enclave to drive as a loaner so I am not complaining. Also found a awesome 2014 SLT crew cab in my favorite color so may have to trade up once they get the old truck fixed up. These new trucks are awesome but I did hear that they tend to catch on fire and they are having to do a software update or something Hmmm

Doug_Scott · January 12, 2014

Dealer likely meant it is a PCV valve free system, not PCV free system. PCV is Positive Crankcase Ventilation, and is still part of just about every engine produced. It simply passes crankcase fumes to the intake so they will be burnt up in combustion. The reasons for an actual valve on earlier engines was to prevent backfires from entering crankcase, and to also control the amount of fume being drawn back into intake. Think of the valve as being variable vacuum leak as well.

They have been using baffles since they first switched PCV type system from the old road draft tube design. I tend to get about 3/4 of a pop can of oil from the PCV oil trap I am using on my 2010 4.8 after about 3,000km. There is a thread here on the subject of the oil trap. Look for the group buy thread, it has good information in it.

I do wonder though, what happens when you add a supercharger to the engine. Cannot really have the engine pressurising the crankcase when under boost. A PCV valve would handle that issue by design (not on purpose).

Dnt · January 12, 2014

Yes my bad I typed it in wrong. A PVC valve is not used on this 2009 5.3 LH6 engine they replaced it with a baffle inside the valve cover and the new design valve cover has a redesigned baffle to prevent or at least slow down the oil going into the intake. sorry about that. I will for sure check on that oil trap but will not make any mods until the GM warranty has run out. Gotta let Mr Goodwrench do all that he can do.... Looked at some FORDs this morning I like the look and feel of a GMC (professional grade) much better. What is up with the ford door panels they shake and flex when you shut and open the door like they are made out of tinfoil??? the Raptor looks pretty cool though. I may have to go look at some Dodge products now. Man that Blue 2014 GMC sure is pretty. I hope it does not catch fire and burn up on the lot before they get the fix in it. Here is a pic of my existing 2009 SLT really like it but if the problems are not resolved I will trade that puppy off.

Dnt · January 14, 2014

update from my dealer they say they have the valve cover change done and fixed the rear main seal leak but say they do not know anything about a AFM deflector shield and cleaning the carbon from the cylinders. Hmmm I guess I will have to send them a copy of the #100601008G:

Engine Oil Consumption on Aluminum

Block/Iron Block Engines with Active Fuel Management

(AFM) (Install AFM Oil Deflector and Clean Carbon from

Cylinder and/or Install Updated Valve Cover) (

Jan 3,

2013)

Fascinating that they could not find that themselves? I do not think since the spark plug fouled that it should be left with the carbon buildup in the cylinders that will create a short life span engine and I want to get at least 300k out of this truck.

Doug_Scott · January 14, 2014

Not trying to make excuses for the dealer, but, some people just have no luck trying to search for something on a computer. If you have the proper name and number of the TSB, give it to them before they attempt to show you how smart they are.

I really do not understand why managment does not see that their employees are not capable of doing a proper search for speciic terms. I have no idea what they use to locate TSB data, but, it must have some user input form they can enter data into. My best guess at what to search for would be "afm, oil, and consumption", maybe toss in "2009". I know some people for whatever reason like to use complete sentences for search terms, and then wonder why that sentence never returns anything.

Dnt · January 16, 2014

OK the latest is that they know about the full TSB but are saying they do not feel it is necessary to do the AFM deflector and the cylinders cleaning. They said that if I want that done I will have to go through the oil consumption test????. They have the valve cover done and the rear main seal leak done and also replaced a O2 sensor which ended up being a cat converter changeout since they stripped the threads out on the O2 sensor fitting when changing it out. They had to replace the entire Y joint piece with the cat. I think I will drive it a awhile and see how it does. I am for sure going to pull ALL the plugs out and inspect them and replace them since I am at 86k and they recommend replacement at 100k anyway. Truck is home in the driveway and all my work stuff is loaded back in What a hassle jeez.

What do you guys think should I push the issue on the AFM deflector and cylinder cleaning??

2014 GMC is too expensive for me. Old truck is not worth a dime and new one is worth more than MSRP LOL not going to be able to deal with them.

Doug_Scott · January 16, 2014

If you have the full TSB on hand, read it and see if dealer is required to do oil consumption test before following the suggested repair. Can't really blame dealership if the TSB has that test as a requirement before replacing parts and cleaning cylinders (not sure what they mean by clean cylinders).

O2 sensor's will likely take the threads with the sensor if they were not installed properly initially. Wonder if they make repair kits for O2 sensors. All it really needs is the bung removed and replaced, if they cannot find a way to replace threads with an insert. They could also make O2 sensors use a flat plate to attach to the pipe. That way if one of the bolts holding the plate on broke coming out, you could just drill it out and re-tap the threads. Be a lot cheaper to repair. Would also be cheaper to repair under warranty.

2014 Sierra's at my dealer all have a $3500 credit on them.

Dnt · January 16, 2014

Here is the full TSB it seems to indicate and/or on the AFM deflector 1/4/13 Document ID: 3242444 and it seems to state that NO oil consumption test would be required. I may be interpreting it all wrong. Let me know what you guys think. So far I am pretty happy with the dealer but I want to make sure my truck is 100% repaired not just patched up till the 100k warranty runs out!!!!

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 1/8

Document ID: 3242444

#100601008G:

Engine Oil Consumption on Aluminum

Block/Iron Block Engines with Active Fuel Management

(AFM) (Install AFM Oil Deflector and Clean Carbon from

Cylinder and/or Install Updated Valve Cover) (

Jan 3,

2013)

Subject: Engine Oil Consumption on Aluminum Block/Iron Block Engines with

Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean

Carbon from Cylinder and/or Install Updated Valve Cover)

Models: 20072011

Cadillac Escalade Models

20072011

Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe

20102011

Chevrolet Camaro

20072011

GMC Sierra 1500, Sierra Denali, Yukon Models

20082009

Pontiac G8 GT

Built Prior to February 1, 2011 (Updated Valve Cover) and October 2010 (AFM

Shield)

Equipped with Any of the Following Engines:

– Aluminum Block V8 Engine with Active Fuel Management (AFM) (RPOs L94, LZ1,

L99, LC9, LH6, L76, LFA, L92)

– Iron Block V8 Engine with Active Fuel Management (AFM) (RPOs LMG, LY5)

– Hybrid Engine (RPO LFA – Only Applies to Hybrid Models Built July 7, 2009 February

1, 2011 – Prior Builds Not Cast For AFM Valve)

Attention: This bulletin does not apply to the Buick Rainier, Chevrolet TrailBlazer and

GMC Envoy equipped with LH6 due to a different design oil pan and AFM

pressure relief valve.

This bulletin is being revised to update the Warranty Information. Please discard Corporate

Bulletin Number 100601008F

(Section 06 – Engine/Propulsion System).

Condition

Some customers may comment about engine oil consumption of vehicles with higher mileage

(approximately 48,000 to 64,000 km (30,000 to 40,000 mi) and a service engine soon light being on

and/or rough running engine. Verify that the PCV system is functioning properly. If the customer

understands that some oil consumption is normal and still feels the consumption level is excessive,

more than 1 quart per 2000 to 3000 miles of driving, perform the service indicated in this bulletin. It

is no longer necessary to have the customer return multiple times to have the usage verified.

Cause

This condition may be caused by two conditions. Oil pulled through the PCV system or oil spray that

is discharged from the AFM pressure relief valve within the crankcase. Under most driving

1/4/13 Document ID: 3242444

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 2/8

is discharged from the AFM pressure relief valve within the crankcase. Under most driving

conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles

(extended high engine speed operation), in combination with parts at the high end of their tolerance

specification, the oil spray quantity may be more than usual, resulting in excessive deposit

formation in the piston ring grooves, causing increased oil consumption and cracked or fouled spark

plugs (#1 and/or #7). Refer to the latest version of Corporate Bulletin Number 120601001.

Correction

Aluminum or Cast Iron Block Oil

in Intake Manifold Install

Updated Valve Cover on All

Models Built Prior to February 1, 2011

Note: If vehicle is built after this breakpoint, it should already be equipped with this updated valve

cover.

1) Old Design

2) New Design

PCV pullover or an overactive lifter can cause oil to be pulled through the PCV system even at low

vehicle mileage. A correctly functioning PCV system will only leave a film of oil in the intake

manifold. Inspect the intake manifold to see if there is any oil puddling in the bottom. If there is you

will need to replace the left valve cover. Two new left rocker arm covers have been released for

trucks and vans. Technicians should replace the left rocker arm cover with GM P/N 12570427 for

20072008

or GM P/N 12642655 for 20092011.

Refer to the Parts Information below for the Camaro.

This rocker arm cover has a relocated PCV drain hole that prevents oil from entering the intake

manifold. Refer to Valve Rocker Arm Cover Replacement Left

Side in SI.

Note: These rocker covers are for specific years. The PCV orifice is different for each. The correct

1/4/13 Document ID: 3242444

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 3/8

cover must be used or an SES light may set.

Aluminum Block Oil

Getting Past Piston Rings Free

Up Piston Rings and Install AFM Shield

on All NonHybrid

Models Built Prior to October 1, 2010 or all Hybrid Models Built July 7, 2009 October

1, 2010

Note: If vehicle is built outside of this breakpoint, it should already be equipped with this AFM shield

or the pan does not have an AFM valve (LFA before July 7, 2009).

To correct this condition, install an AFM shield, perform the piston cleaning procedure as described

in this document and install a new oil pan gasket per the procedure outlined in this document.

Monitor oil consumption after this repair to ensure oil consumption has improved to acceptable

levels.

If this repair does not correct the condition, it may be necessary to replace all of the piston

assemblies (piston and rings) with new parts. Refer to SI for repair procedure.

Important: It is critical in this cleaning process that the engine/fuel injector cleaner remain in the

cylinders for a minimum of 2.5 hours to fully clean the components. The cleaner solution must be

removed before a maximum of three hours.

1. Remove the spark plugs and ensure that none of the pistons are at top dead center (TDC).

2. Clean the pistons by putting 118147

ml (45

oz) of Upper Engine and Fuel Injector Cleaner,

GM P/N 88861803 (in Canada, use 88861804), in each cylinder. Allow the material to soak

for at least 2.53.0

hours, but no more than three hours and then remove the cleaner. A

suggested method of removing the cleaner is cranking the engine over. Make sure to

unplug the ignition coils and fuel injector before cranking the engine over. Also make sure

that the painted surfaces are covered so no damage is done.

3. Remove the oil pan. Refer to Oil Pan Replacement in SI.

4. Remove the AFM valve (1).

1/4/13 Document ID: 3242444

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 4/8

5. Install the new shield (1), GM P/N 12639759, and tighten the AFM valve to the oil pan to 28

N·m (20 lb ft).

Important: Ensure that the engine cleaner is thoroughly removed before reinstalling the

spark plugs. Failure to do so may result in a hydrolock

condition.

6. Reinstall the spark plugs. Replace the spark plugs if necessary due to full of carbon. Refer

to the parts catalog.

7. Reinstall the oil pan. Refer to the Oil Pan Installation procedure in SI. Replace the oil pan

gasket if necessary. Refer to the parts catalog. Replace the engine oil.

8. Reevaluate

the oil consumption. Document on the repair order. If the oil consumption is

still greater than 0.946 L (1 qt) in 3,200 km (2000 mi), replacement of the pistons and rings

will be required.

Important: Some minor scratches may be noticed on the cylinder walls during piston and ring

replacement. If the scratch cannot be felt when running your finger nail over it, the scratch is

considered normal wear and the block or engine should not be replaced.

Note: It is not necessary to hone or deglaze the cylinder walls. Honing may induce unnecessary

cylinder wall and / or piston ring damage if it is done incorrectly and/or not cleaned thoroughly.

Cylinder walls should cleaned thoroughly with brake cleaner before installation of the new pistons

and rings. Numerous engines replaced for oil consumption have been inspected. The cross hatch has

been consistently good and is in specification. As a result, is should not be necessary to measure the

cylinders if they pass the visual inspection.

Note: After the piston/ring replacement it will take 20003000

mi. for the new rings to seat.

Adequate break time is necessary prior to rechecking the oil consumption level.

Note: Do not overlook the valve seals at higher mileage. Look in the head ports for evidence of

excessive amounts of oil getting past the seals.

1/4/13 Document ID: 3242444

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 5/8

Note: It is recommended to install an AFM shield any time that the oil pan is removed for any

reason and an AFM shield is not found.

CastIron

Block Oil

Getting Past Piston Rings Free

Up Piston Rings on All Models Built Prior

to October 1, 2010

1. Remove the spark plugs and ensure that none of the pistons are at top dead center (TDC).

2. Clean the pistons by putting 118147

ml (45

oz) of Upper Engine and Fuel Injector Cleaner,

GM P/N 88861803 (in Canada, use 88861804), in each cylinder. Allow the material to soak

for at least 2.53.0

hours, but no more than three hours and then remove the cleaner. A

suggested method of removing the cleaner is cranking the engine over. Make sure to

unplug the ignition coils and fuel injector before cranking the engine over. Also make sure

that the painted surfaces are covered so no damage is done.

Important: Ensure that the engine cleaner is thoroughly removed before reinstalling the

spark plugs. Failure to do so may result in a hydrolock

condition.

3. Reinstall the spark plugs. Replace the spark plugs if necessary due to full of carbon. Refer

to the parts catalog.

4. Reevaluate

the oil consumption. Document on the repair order. If the oil consumption is

still greater than 0.946 L (1 qt) in 3,200 km (2000 mi), replacement of the pistons and rings

will be required.

Note: It is not necessary to install the shield when doing the piston cleaning on a cast iron

block engine since the cast iron block engine uses a different oil pump than an aluminum

block engine, which results in a higher engine speed before the AFM pressure relief valve

opens (cast iron block engines are less prone to the AFM oil spray condition described

earlier). If you find it necessary to replace the pistons and/or remove the oil pan for any

other reason, only then should you add the shield.

1/4/13 Document ID: 3242444

gsi.xw.gm.com/newsi/showDoc.do?docSyskey=3242444&from=nb 6/8