So, I have a two year history of oil consumption. Here's my chain of events in case anyone else may run into a similar aggravating story. Or if you just want to read my rant.

Right off the bat, I'm out of powertrain warranty and went back to the original dealer (who got bought out) a couple weeks ago and talked with the service manager about replacing my left/driver side valve cover for PCV oil consumption. He called GM and they said it'll be about $600 to perform the TSB. I said I've already had the bottom end looked at so there's no point in ripping the oil pan off again. I asked if he could please call them back and see if they'll give me a reduced cost for the top-end part only since that's all I need.. de-carbon cylinders, valve cover, spark plugs, maybe clean out the throttle body if it's dirty. He finally called me back and said $50. Good nuf fer me. It's going in Thursday.

Here it goes. 'other dealer' and 'original dealer' is because I don't want to say any names.

Purchased June 28 2014 - GM Certified one owner 56k miles - 2011 Silverado Z71 w/ LC9/6L80E - door tag build Nov/2010 - originally sold Feb 2011

December 2014 - brought into original dealer for regular maintenance. Mentioned rough idle. Service writer suggested fuel system cleaner for one tank.
**no change

May 2015 - brought into original dealer for second regular maintenance. Mention rough idle again, as well as rough shifting and AFM does not engage after drive to/from work (10-12 hwy miles).
**"no codes stored", received quote for trans flush & new tires (the tires are fine, shut up)

October 2015 - brought to 'other dealer' service dept. Rough idle, rough shifting, lifters and/or valve train noisy. Stabilitrack and traction control off.
**steering position sensor fault - replaced
** "oil level very low, nothing on stick, might be piston rings"
**start consumption test

November 2015 - first 1k miles on consumption test
**oil level full

December 2015 - 2k miles on consumption test
**1/2 quart low - topped off
**rode with shop foreman to hearing clanking/pinging - "could be lifter or valve spring causing noise"
**asked to call GM rep to authorize checking rockers, springs and guides and then lifters if problem is found - no call returned

January 2016 - 3k miles on consumption test
**1/2 quart low again - topped off
**asked to call GM rep again - no call returned again
**NO repair order

February 2016 - ~3400 miles - 1/2 quart low again, check myself - shifting rough again - AFM not engaging again - 20psi at idle, 25psi at 70MPH
**stated fuel mileage at 12MPG - "winter gas sucks" was the excuse
**asked to call GM again about valve train noise and pinging, service writer says "we don't need to call, there's nothing wrong"
**poor to no documentation, hand written notes of ride with foreman - unacceptable, complained
**no explanation for decreasing oil pressure after 3k miles
**refused any further service "no SES, everything within GM specs, nothing we can do"
**requested oil change - now 30psi at warm idle, AFM works fine again after fully warmed up and 40psi with highway driving @ 70MPH

February 2016 again - brought back to 'other dealer' again to speak with service managers
**service manager drove in morning - inoperative AFM experienced - shutdown and restart resolved (not the solution I'm looking for)
**oil pan removed and inspected - no metal in pan
**AFM pressure relief valve replaced
**AFM shield on pressure relief valve already in place - replaced anyway
**new o-ring on sump tube
**lifter oil screen replaced - no metal or sludge in old screen
**oil pressure sending unit replaced
**valve lifter oil manifold replaced - ovaled gasket passages
**compression testing on cylinders returned fine (or so I was told)
**no repair order for ANY of this again! Yet VLOM replacement shows up on GM warranty repair list

I really think they were trying to run out the powertrain warranty on me here. Shady bastards.

March 2016 - very experienced and competent mechanic drove it
**pinging/clicking/knocking is "spark knock" aka detonation - 'other dealer' completely misdiagnosed
**oil burning = carboned cylinders = rough idle, possibly carboned and oil fouled plugs, knocks sensed causing PCM to retard timing (the hesitation I feel often)
**oil consumption would be very high if majority of control rings are inoperative/stuck
**bad lifters are very noisy, you'd know it
**suggested Techron and premium gas for a couple tanks and drive a bit more aggressively, don't be afraid to open it up on the highway and hit the rev limit
**if it won't clear up, try carbon cleaning cylinders and check PCV system, possibly replace valve cover, check for TSB 10-06-01-008G (perform TSB if it's a quart within 2-3k miles and the customer expresses a concern.. you're damn right I'm concerned after two years of this crap!)

May 2016 - ~2800 miles
**1qt of oil has been added since change in Feb
**now noticed left valve cover has some leaking spots
**oil pressure starting to decrease during highway driving again, same old story

June 2016 - ~3400 miles
**added another 1/4 qt of oil
**starting to shift rough again
**oil pressure around 25psi after fully warmed up and highway driving, AFM does not operate again
**back on 87 gas - knocking returned, so that's that

I give up on Dexos bulk oil, it does not last beyond 3k miles and will not maintain pressure for AFM to operate as designed.
At this point, I just want the oil burning and resulting carbon fouling to stop. Powertrain warranty is up, going to have AFM disabled anyway. 3k mile oil changes from here on out. I don't have the time nor patience to play mechanic.

 

Left valve cover replaced and new oil/filter yesterday. We'll see what happens with the consumption over the next couple thousand miles.

Tech got oil everywhere and didn't clean it up. Left the stupid top plastic vortec cover unseated. And broke the retainer clips on the harnesses that attach to the coil pack mounts on both sides. I give up on dealer mechanics. They're ****ing idiots.

 

I haven't seen to many people happy with GM service or mechanics over the past few years. Me being one of them. They love to band-aid the underlying problem it seems. I thought the oil consumption problem was fixed by 2011 though, guess not though.

 

My 2011 was built in November 2010. It has consistently burned a quart in 2500-3000 miles. If the oil control rings were stuck on mine, it'd be burning at least a quart per 1k. TSB 10-06-01-008 and subsequent updates to it (it's now at 008M) addresses the left valve cover problem. The one I printed and took with me and showed to the service manager was 008G dated Feb 2011. So mine did not yet have the updated valve cover. That TSB says 1qt in 2-3k could be due to the baffle drain location and size in the older valve cover. Oil would shoot up from the push rods into the baffle and not drain, allowing the PCV to suck the oil into the intake. The PCV should remove vapors from the crank case and very little if any oil (a thin film of oil in the throttle body is "normal").

If this doesn't cut my consumption down to say 1/4qt in 3k, then I'm going to get a tuner to shut the AFM off. I haven't yet because it was still under PT warranty until this past Feb, but I didn't want to mess with anything until I got GM to finally do the valve cover. The service manager was able to get the GM rep to knock it down from about $600 to $50, mostly since I didn't need the pan dropped and the shield over the AFM valve installed which was already done by the other dealer.

 

no point in putting on a new valve cover. everything built after nov 2009 already has the updated part to my knowledge....I could be wrong. the tsb release date was 2008 correct

 

10-06-01-008G has 2011 models on the list, so it is affected.

Models: 2007*-2011 Cadillac Escalade Models
2007*-2011 Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe
2010*-2011 Chevrolet Camaro
2007*-2011 GMC Sierra 1500, Sierra Denali, Yukon Models
2008*-2009 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)

 

And I might add that I found it pretty stupid that I had to dig through the internet to find a document and present it to a dealer so that they would call their GM rep to get **** done. I am utterly disgusted that at almost every turn, all I got was "there's nothing wrong."

My entire family has been GM owners forever. Well, I'm done. This is the last that I'll ever buy. Loyalty gets you nothing anymore.

 

I agree with the loyalty gets you nowhere nowadays. I love GM because I can work on them, I'll never buy another new one though. When you delete the AFM, don't be surprised when your fuel mileage increases. Every one I know personally that has had it shut off has had a noticeable bump in mileage, I have read online a few people that didn't gain nor lose. All that crap that is supposed to increase mileage from the factory is a joke.

 

So, for about the past year, I've been checking my oil level once a week on Wednesdays when I get to work (15 mile drive, shut off and let it drain down for a minute or two, pull and wipe the stick three times). I'd be at least a 1/2qt low every month.

Now I'm at almost 2k miles since the valve cover replacement and oil change and I've lost... none. So now we know where the oil loss and resulting carbon fouling was coming from, which the carbon cleaning didn't fix because it's still knocking.

So thank you GM for ignoring my problem for two years. I hate you.

 

A little late to the party here but if someone reads this would like some info also. My truck is a 2011 85k and just started smoking. Really only notice it on start up but does it even when its warm so not acting like old valve guides. Wondering if the PCV could be part of the issue. Also using oil now which it never did before.