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  1. #191

    Default

    On the highway im getting 18-20 with what i have done...pulling my 30 foot camper im getting 13ish...so that i think is pretty good for pulling a 5500lb camper...i love chevy and i will always stick with GM

    2009 Chevrolet Silverado 1500 LT Z71 Crew Cab "All-Star Edition"

    Line-X'd Bed
    Line-X'd Custom Brush Guard(Heavy Duty)
    5.3L Flex Fuel
    275/65R18 Toyo Open Country AT2's
    2" Rough Country Leveling Kit(want to get the 2.5 RC kit)
    EGR In-Channel Vent Visors
    Exterior PLUS Package
    Interior PLUS Package
    K&N Drop-In Air Filter
    ProFlaps
    Cat-Back Dual Exhaust
    Black Bowties
    Diablo Sport Predator(AFM Disabled)
    ProFlaps
    Towing Mirrors
    Next Planned Mods
    Blacked out Tail Lights
    Aftermarket Rims

  2. #192

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    Quote Originally Posted by phoebeisis View Post
    ChevyBoy-GM was stuck-they HAD to match Ford dodge Toyota-AFM was the only way to get 16/23 with 360 hp pushrod V-8

    The 5.3 has only had two real problems
    the funny piston slap like noise from carbon accumulating above the top ring
    and this oil consumption problem on some of the AFM motors
    On the bright side
    the latest 5.3 is 16/23 with 360 hp
    I think that they had 3 and mine was one! Lifter bleed, mine clattered after sitting over-nite! A new lifter kit, solved my issue.
    2010 GMC SIERRA CREW CAB (Silver) 4x4, ReadyLift 2.5" Level Kit, 305/60/18 Dick Cepek Mud Country, Go Rhino Nerf Bars, Husky Liners front and rear, Bushwacker Bed Rail Caps, SCT Programmer.

  3. #193
    Legend

    Join Date
    Jun 2006
    Location
    River Ridge Louisiana-4 miles W of New Orleans-didn't flood-water stopped 800 yards away.
    Posts
    1,613

    Default

    Right-forgot about that
    1998 suburban-
    1/2 ton

    199500 miles
    River
    Ridge,LA

  4. #194

    Default

    Quote Originally Posted by ChevyBoy2009 View Post
    Why do you say that,have proof to back up your statement?...it started this issue within last couple months,i caught it quick...i have my hopes up that it fixed it,if not ill take it back in...if im still having issues within the next year(powertrain warrenty is up then)ill get back up into a dmax

    - - - Updated - - -

    Im also going to get a programmer and delete AFM and keep it off for good

    Was told in person by the service director and service tech at my dealership when I had the same procedure done on my truck that you just had done.
    Only fix is new pistons and rings, lower end rebuild pretty much. Feel free to search the internet and find someone that only had to do the new valve cover, pan baffle and cylinder cleaning and it fixed the problem.

  5. #195
    Legend

    Join Date
    Jun 2006
    Location
    River Ridge Louisiana-4 miles W of New Orleans-didn't flood-water stopped 800 yards away.
    Posts
    1,613

    Default

    I'm still not sure of the WHY
    Why does this happen with the AFM motors?
    Oil only can get in the combustion chamber in 3 ways I think(assuming no intake manifold gasket oil leak to intake side)

    1) Rings not working right
    2)Valve guide seals not sealing
    3)Maybe PCV valve letting too much oil mist into intake-not sure that can happen

    So what is it??
    And if the "easy fix" doesn't work-why would new rings pistons etc work
    IF they are the same as the original rings pistons etc?

    I'm wondering if perhaps when a cylinder isn't combusting- you don't get a good ring seal- because combustion pressure usually pushes the rings outward-and forces a better seal-and scrapes the oil off better too??

    So WHY AFM?
    What do the mechanics service managers who have done the "BIG FIX" say is the problem??
    Tigerwith a88'S info seem to imply they are putting in rings with more outward spring.

  6. #196

    Default

    Charlie: A lot of the issue with the AFM system losing oil has to do with individual cylinder and piston cooling, when a cylinder is shut down even for a few seconds it begins to cool, the piston and rings also cool but at different rates than the cylinder being the neighboring cylinders are still producing heat and transfering it via the block.
    GM engineers believe via this method the rings are allowing excessive oil loss due to the differing cooling rates.
    Under normal circumstances a cylinder, piston, and rings would cool at a much closer rate being that all cylinders would be not running/building heat, which in turn wouldnt be transferred to the non-running cylinder.
    Something engineers seemed to over look or just didnt care about was the old NorthStar 1st gen engines (late 70's and early 80's) were terrible about oil fouling the plugs. GM had a recall for them around 81/82 to put an anti fouling extension in the block for the plugs and to swap the factory plugs for a hotter version. A friends mom went through 2 engines on her 80 Sedan Deville before the vehicle was bought back by Caddilac. Those engines used the same cylinder shutdown theory being used now, technology has gotten better but obviously it has developed enough to defeat all the old gremlins.

  7. #197

    Default 2009 chevy avalanche engine issues

    I have 2009 Avalanche LTZ with 90,000 miles on the vehicle and have lifters that just collapse. The dealer denied my warranty and said it had poor maintenance. I cant believe that they would do this when this is happening all over. I filed a complaint with GM and have not got any results. I paid another well qualified Mechanic to fix the issue and I'm currently thinking about filing a complaint with the state attorney general office. This is ridiculous that this problem is happening to a lot of people and they are not fixing the issue. I spent a lot of money on this truck. I will never buy chevy again and they should of let this company fail since they care more about numbers then customers. Also it took the dealer 3 days to tell me they were not covering the repair. Maybe if enough of us get together we can get them to admit that there is an issue.

  8. #198
    Legend

    Join Date
    Sep 2010
    Location
    everett, massachusetts
    Posts
    1,449

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    Quote Originally Posted by tbplus10 View Post
    Charlie: A lot of the issue with the AFM system losing oil has to do with individual cylinder and piston cooling, when a cylinder is shut down even for a few seconds it begins to cool, the piston and rings also cool but at different rates than the cylinder being the neighboring cylinders are still producing heat and transfering it via the block.
    GM engineers believe via this method the rings are allowing excessive oil loss due to the differing cooling rates.
    Under normal circumstances a cylinder, piston, and rings would cool at a much closer rate being that all cylinders would be not running/building heat, which in turn wouldnt be transferred to the non-running cylinder.
    Something engineers seemed to over look or just didnt care about was the old NorthStar 1st gen engines (late 70's and early 80's) were terrible about oil fouling the plugs. GM had a recall for them around 81/82 to put an anti fouling extension in the block for the plugs and to swap the factory plugs for a hotter version. A friends mom went through 2 engines on her 80 Sedan Deville before the vehicle was bought back by Caddilac. Those engines used the same cylinder shutdown theory being used now, technology has gotten better but obviously it has developed enough to defeat all the old gremlins.
    good answer on this. gm failed big with this in the 80's.

  9. #199
    Jr. Engineer Cowpie's Avatar
    Join Date
    Jun 2013
    Location
    Central Iowa
    Posts
    216

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    Quote Originally Posted by ChevyBoy2009 View Post
    ...intake was soaked in oil...they tipped it over and oil poured out i guess

    I can believe that. With the 3 full shot glasses of oil and other contaminates that my PCV oil catch can captured in 6000 miles, I am sure glad I put it on my 2013 5.3L. That would explain how your intake was soaked in oil. I capture it before it makes it to the intake. Imagine that stuff caking on the intake valves. And it is common knowledge, that oil in the combustion chamber will reduce the octane rating of the fuel and possibly cause the ECM to revert to other settings to compensate for knock and that would be a bad thing for fuel mileage.

    Not stopping a simple problem can lead to more difficult problems.

    As opposed to doing reactive maintenance, I chose the proactive route with my 2013. I really was not aware of these AFM issues when I actually bought it, it was in doing more reading and searching online about the ride before picking it up after the dealer final touches that I came across all of this stuff. So, right out of the gate when I brought the pickup home, new, from the dealer, I shut down the AFM function on the engine and installed an oil catch can. I dumped the factory fill oil at 1190 miles, and filled with full synthetic.
    Hey there, VA, what do ya' say? How many vets did you kill today?

  10. #200

    Default

    Great I just bought a 2008 with 70k miles on it. Doesn't seem to have any problems as of yet and had a clean carfax report.
    It replaced my 1999 suburban.

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