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2011 Very Rough Idle, Misfire on cyliner 7

I am trying to get to into my dealer this week for the same TSB. I told them I was doubtful it would help my oil consumption issue.

I also stated to her (my service manager) that I would pay to have my AFM turned off. She looked into it and said that it would never "officially happen" but a diagnostic fee could be charged for a "No Fault Found" issue but when I leave the dealership, she doesn't want to hear any complaints of "not going into V4 mode" or "my AFM isn't working"
 
Kinda excited to see if she can do it for me, but even if she does I won't be able to post it here as it "never officially happened"
 
I am unofficially hoping things work out as you have planned.

(y)
 
I have a 2011 LTZ with 17,000 miles on it and the rough idle has started only while in gear and standing still. Is disabling the AFM the only way to correct this problem and does this impact the warranty? Another question I have is if GM can't solve the problem, is this a "lemon law" issue to pursue? I do love my Avalanche and was not aware of this problem prior to buying a year ago and sure wasn't told by the saleman!! I have had it back twice and service says, "no code found", it a common problem with this engine!
 
EMSDC said:
I have a 2011 LTZ with 17,000 miles on it and the rough idle has started only while in gear and standing still. Is disabling the AFM the only way to correct this problem and does this impact the warranty? Another question I have is if GM can't solve the problem, is this a "lemon law" issue to pursue? I do love my Avalanche and was not aware of this problem prior to buying a year ago and sure wasn't told by the saleman!! I have had it back twice and service says, "no code found", it a common problem with this engine!
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There should be no way your truck is having issues already unless your not using the proper oil or not changing the oil at the right intervals. Its too young with too few miles. Just sayin. Maybe theres something else at work here
 
Thanks Krazycarguy, I change the oil with regular 10W30 every 3000 miles, would that impact the way it is starting to idle? This is the first of hearing the type of oil may cause this problem!!
 
Your supposed to be running GM's DEXOS oil. Its a special synthetic blend for GM's 2011 and newer. Could that cause an issue? Yes. Did it? probably not. lol. My engine has always seemed to stumble ever so slightly at idle, but i owned a 4 banger before this, so it doesnt bother me any, and the truck seems to be running fine. Do you have a significant stumble or is it just slight?
 
I think it's significant but it differs at times - sometimes the tach bounces as well. I have not looked at the oil pressure which I will next time. I really notice it while waiting for a red light in gear with the brake on!
 
I have a 2011 Chevy Avalanche, I bought it new Love the truck, hate the engine, many issues in the past year with misfiring and check engine light comming on.
Issues with Burning oil, Check engine light on. Dealer found a misfire in cylinder #1 and 7. Started with 39167 miles, I've been to the dealer 3 times they have done the following repairs:
first visit 11/19/12 replaced spark plugs due to being fouled and dirty, cleared DTC's and replaced oil.
Second visit - 3/8/13 miles 50639-- Check engine light on, running rough / Misfire - Dealer install SOP, verified - DOC 10-06-01-008I installed AFM oil defector and updated valve cover. Performed upper engine cleaning as outlined in document # 10-06-01-008I
On 4/12/13 - Engine misfire check engine light on Miles 54699 - Dealer received fault codes -P0301, P0305, P0307. removed spark plugs, oil fouled , disassembled found excessive carbon on piston tops, ring lands and combustion chambers.
installed new pistons, rings, bearings and all necessary gaskets. cleaned carbon off cylinder heads. replaced spark plugs. cleared fault codes.
on 6/7/13 check engine light come on again, engine misfiring, pulled into service center, engine low on oil, filled oil. Engine making noise and still misfiring.

Time for new engine? Let's see what the dealer will do now -
 
hvyseas said:
I have a 2011 Chevy Avalanche, I bought it new Love the truck, hate the engine, many issues in the past year with misfiring and check engine light comming on.
Issues with Burning oil, Check engine light on. Dealer found a misfire in cylinder #1 and 7. Started with 39167 miles, I've been to the dealer 3 times they have done the following repairs:
first visit 11/19/12 replaced spark plugs due to being fouled and dirty, cleared DTC's and replaced oil.
Second visit - 3/8/13 miles 50639-- Check engine light on, running rough / Misfire - Dealer install SOP, verified - DOC 10-06-01-008I installed AFM oil defector and updated valve cover. Performed upper engine cleaning as outlined in document # 10-06-01-008I
On 4/12/13 - Engine misfire check engine light on Miles 54699 - Dealer received fault codes -P0301, P0305, P0307. removed spark plugs, oil fouled , disassembled found excessive carbon on piston tops, ring lands and combustion chambers.
installed new pistons, rings, bearings and all necessary gaskets. cleaned carbon off cylinder heads. replaced spark plugs. cleared fault codes.
on 6/7/13 check engine light come on again, engine misfiring, pulled into service center, engine low on oil, filled oil. Engine making noise and still misfiring.

Time for new engine? Let's see what the dealer will do now -
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Sounds like it was time for a new engine when the dealer first touched it......funny how all those new parts didn't solve the problem........of all of the posts on this board and other boards re: AFM problems I've seen where they replace pistons and rings it never mentions what measurement and treatment was done to the cylinder walls during the process. If the walls are scuffed or out of round because of wear (quite possible running with frozen rings that caused the problem, to begin with) the only solution is to rebore oversize and use oversize pistons/rings. Even if the cylinder wall is perfectly round (unlikely if there are significant miles on it) you have to at least re-hone with abrasive stones to break the glaze on the cylinder walls......if you don't break the glaze you may as well throw the new rings in the garbage because they will never seat or break-in properly. Of course that would make a big job a major job because you have to dismantle and redo the whole bottom end to resurface or bore the cylinders oversize (I doubt many dealers are equipped to do the latter in house....and that is if it is even possible on this Al engine.... steel wall liners may be too thin to rebore or worse impossible if the engine lacks liners altogether). If new pistons/rings didn't solve the problem this soon and they won't give you a rebuilt engine or send it to an engine shop for rebuilding, trade it in while you can still get a decent price for the trade.
 
Wejust got a 2014 silverado in here yesterday.  The crank case is under a small vacuum, via a belt driven pump. It will help with the oil consumption.
 
Just bought the Range AFM Disabler. Plug and play and I love it. It took care of the rough idle and ride when the V8/V4 switched back and forth. Love this device! Makes my 2011 Ava drive and ride like a dream - So Happy!!
 
Zman, it sounds like you got a Lemon.  My 2011 LTZ has 26.000 miles on her and 0 problems. same with the 2010 and the new 2013.  :B:.  time to look into the Lemon Law in your area.
 
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