07 'Burb - what to do first?
October 1st, 2013, 7:56 AM
#11
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The issues I have heard on the AFM is that the AFM lifters fail by coming apart or collapsing... from what I have read in the forum the fix is a top engine rebuild of new lifters and cam....
October 1st, 2013, 8:27 AM
#12
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October 1st, 2013, 3:32 PM
#13
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No idea. Bought it at 76k and has 79k now. I checked it before I bought it and again once I got it broken in, and it was still clean. Oil life was about 90% at the time too. I'm gonna change it myself next chance I get.
October 1st, 2013, 6:53 PM
#15
I have the 5.3 'flex fuel', with AFM. I'm almost 100% positive that the 6.0 doesn't have AFM in 2007 (I -think- that's standard now though), so you wouldn't have the issue.
AFM disables 4 cylinders for 'economy', think 'displacement on demand' in the old Cadillacs.
In any event, the AFM system has been rumored to cause carbon buildup on the piston rings of deactivated cylinders, eventually leading to burning oil (which you may or may not notice in the exhaust).
I've only had the truck for less than a week, so I have no idea if it has the problem (yet) or not.
AFM disables 4 cylinders for 'economy', think 'displacement on demand' in the old Cadillacs.
In any event, the AFM system has been rumored to cause carbon buildup on the piston rings of deactivated cylinders, eventually leading to burning oil (which you may or may not notice in the exhaust).
I've only had the truck for less than a week, so I have no idea if it has the problem (yet) or not.
October 2nd, 2013, 6:21 AM
#16
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Given that you have less than 100k miles, you may have good results taking it to a dealer, and having them do the 'oil consumption test'. You might have to jump up and down a bit, though, as it seems to depend on the dealer as to whether they will give much assistance.
I believe that ultimately, GM replaces the pistons and rings, after trying everything else. Best to get them to start the process of 'everything else'...
I believe that ultimately, GM replaces the pistons and rings, after trying everything else. Best to get them to start the process of 'everything else'...
Thinking about a Black Bear tune as he'll be here locally in December. But if the problem is already here, the tune isn't going to fix it.
That's what it appears. I won't really know until I change it and run a few more thousand through it, but I don't think I'm going to wait that long.
October 2nd, 2013, 1:46 PM
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Well spoke to a gentleman in service at the dealer and he explained that GM Engineers have tested and expect a loss of up to 1 quart of oil every 2000 miles in an Active Fuel Management vehicle. Whoa that seems like a lot.
My warranty has expired so looks like I'm on my own.
Thanks for the help guys.
My warranty has expired so looks like I'm on my own.
Thanks for the help guys.
October 2nd, 2013, 2:38 PM
#18
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What oil are you running conventional or synthetic? I have an 07 with the 5.3 AFM 87,000 miles, used Mobil 1 since day one and have not experienced any oil consumption issues, I go by the OLMS and change oil about every 8,000...
October 3rd, 2013, 2:51 PM
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engine power is reducing, stabilitrak needs service, and traction control off causes vehicle to slow to 25-30 mph then shut off, that is what i am experiencing as we speak and so far there is no actual solution to this problem without spending thousands of dollars going through the process of elimination and repairing all sorts of things till its fixed, i have an 07 burban and it has 89,000 miles. this same issue that i am having seems to be one that a lot are having as well.