5.3l afm engine tick--not the typical lifter tick @ cold start

Discussion in 'GM Powertrain' started by alkaspeltzar, Apr 8, 2011.

  1. alkaspeltzar

    alkaspeltzar Member

    2010 5.3 Silverado, w/ 6 speed and AFM. ~20,000MILES

    The truck drives smooth and no ticking in general. But when it drops to its lower gears, near 1000-1200rpms, and you apply light throttle/load, you can hear some ticking just for a second. Usually then the tranny downshifts, rpms rise, and it goes away.

    I have checked the exhaust, no problems there.

    I have checked the lifters/valves at dealership, no problems there. This is not the typical lifter tick at startup!

    I have been told it could be sound, resonating through the exhaust as the engine lugs....or it could even be the fuel injectors firing? Anyone confirm this? Anyone with the same truck hear this on the drivers side?

    Your help is greatly appreciate. Thanks
  2. dpeter

    dpeter Epic Member 5+ Years 500 Posts

    Could be slight ignition knock and when sensed it downshifts to aleviate the condition. Try a tank of premium gas next time and see if it improves or goes away. If it does then maybe program issue in computer.
  3. squires

    squires New Member

    I have the same issue with my 2010, dealer told me that it was due to the AFM. my 2007 never had this issue, it is suposedly a well know service department complaint that stems from a few different things.07 had a 3.73 rear, 4 speed. The 10 has 3.42, 6speed they left alot to be disired in the synching of the gears in my mind. The fuel reduction was not enough in the first generations of the AFM, so they now try to maintain the V4 mode longer than the first generations, resulting in the vibration (again told it is the exhaust resonating through the system) and the sloppy spiratic shifts in low throttle scenarios.I would like it all disabled by GM, let the owner decide if they want tp "save" fuel, i think it is an emissions spoof myself, my 10 if anything is worse than my 07
    Last edited: Apr 28, 2012
  4. O'Brien

    O'Brien Member

    All true.Problem is getting Gm to acknowledge it. And,that ain't gonna happen. Id like to see an honest poll of how many consumers weren't aware of the cylinder unloading feature of the 5.3 AFM before purchasing it. Of course noone wants to come across as being an unwary consumer so some may say they were but in reality were not aware of it.The sales people sure don't push the issue much and nowhere on the window sticker does it elude to anything except the letters AFM,which mean nothing to most consumers unless they did some homework first. In my opinion the whole inception of the AFM is sort of a don't ask don't tell policy of sorts. Too bad GM felt obligated to butcher such a nice powerplant as the 5.3. Heck,they were selling Colorados with the 5.3 option without AFM. Go figure.
  5. ippielb

    ippielb Epic Member 5+ Years ROTM Winner 1000 Posts

    Some distributors(one out of the 8) like to tick, does it do it when it's not in gear? Give it a listen.

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