Jump to content

Recommended Posts

Posted
5 hours ago, Snoringbear said:

How/why would AFM cause excessive oil consumption?  Not being argumentative just wanting to learn.

Not really sure why it helps, but I know it works. I'm sure there's a thread on here about it. Fixed my oil burning issues.

Maybe it has something to do with a lack of pressure in the cylinders that are disabled allowing oil to pass through the piston rings?

Read some horror stories of excessive carbon build up in the combustion chamber caused by the AFM.

Posted
17 hours ago, lylknutsak said:

Not really sure why it helps, but I know it works. I'm sure there's a thread on here about it. Fixed my oil burning issues.

Maybe it has something to do with a lack of pressure in the cylinders that are disabled allowing oil to pass through the piston rings?

Read some horror stories of excessive carbon build up in the combustion chamber caused by the AFM.

Put a catch can on it. They burn plenty of oil on blow by, the catch can helps with that and keeps the intake cleaner.

Posted
37 minutes ago, evlwhtman said:

Put a catch can on it. They burn plenty of oil on blow by, the catch can helps with that and keeps the intake cleaner.

And the direct injection keeps fuel from cleaning the tops of the valves :(

Posted
On October 24, 2017 at 9:05 PM, lylknutsak said:

Not really sure why it helps, but I know it works. I'm sure there's a thread on here about it. Fixed my oil burning issues.

Maybe it has something to do with a lack of pressure in the cylinders that are disabled allowing oil to pass through the piston rings?

Read some horror stories of excessive carbon build up in the combustion chamber caused by the AFM.

Took your advise and found this link.  Seems to provide pretty good info.  Apparently GM has acknowledged that there can be a problem with some vehicles. 

https://parts.olathetoyota.com/blog/4920/gmc-chevy-afm-oil-consumption

 

just a side note; my driver prior to my current 2015 Silverado 6.2 was a 2008 Silverado 5.3.  It had AFM and at 140,000 miles when I traded it in engine was still tight, maybe down a half quart at 5,000 mile oil change time, especially if I had been doing some long distance towing.  Btw, my current driver, 2015 Silverdo 6.2 is tight as a drum, zero oil consumption.  Just another input from my search;  appears the recommended 0 / 20 weight oil having lower viscosity than previous recommended weights can cause oil consumption if engine tolerances aren't tight enough. 

 

 

  • Thanks 2
Posted

I found the above link too and have not disabled AFM yet, however I burn 1.5 to 2 qrts every 3,000 or so miles, depends how i drive it. And to bring this back to the topic, I too have the shakes, very noticeable around 76-80mph for me, and with speed limit 70 around me, I'm either the slowest (under 74mph)  or fastest guy (above 82mph) out there so we dont get sick in the car by vibrating. 

  • Like 1
Posted
5 hours ago, EFLine said:

I found the above link too and have not disabled AFM yet, however I burn 1.5 to 2 qrts every 3,000 or so miles, depends how i drive it. And to bring this back to the topic, I too have the shakes, very noticeable around 76-80mph for me, and with speed limit 70 around me, I'm either the slowest (under 74mph)  or fastest guy (above 82mph) out there so we dont get sick in the car by vibrating. 

This bad at 76-80? 

IMG_0511.MOV

Posted
18 hours ago, Dmf10e said:

This bad at 76-80? 

IMG_0511.MOV

So its just a thought and I only say this out of curiosity. So with you having a bench seat in the middle, I wonder if that "shows" more effect of the shake then say mine with the captains chairs in front because my cup holders/arm rests are also not on a pivot and cant rattle to the extreme that yours can? I only say this because I have had about 10 loaner trucks from GM, some shake and i see the effects in the arm rest more so on the bench seats than i do on mine, HOWEVER, it feels the same in the chair in both cars but the effects are not shown as extreme on mine. 

 

if you youtube "Chevy Shake" it appears that most of the videos are of people with the bench seat, just my observation. 

 

Ha, I am no engineer so maybe that has absolutely nothing to do with it. 

  • Like 1
Posted
5 hours ago, EFLine said:

So its just a thought and I only say this out of curiosity. So with you having a bench seat in the middle, I wonder if that "shows" more effect of the shake then say mine with the captains chairs in front because my cup holders/arm rests are also not on a pivot and cant rattle to the extreme that yours can? I only say this because I have had about 10 loaner trucks from GM, some shake and i see the effects in the arm rest more so on the bench seats than i do on mine, HOWEVER, it feels the same in the chair in both cars but the effects are not shown as extreme on mine. 

 

if you youtube "Chevy Shake" it appears that most of the videos are of people with the bench seat, just my observation. 

 

Ha, I am no engineer so maybe that has absolutely nothing to do with it. 

Yeah I thought about that. Just seems hit or miss on here. Some people don't have the issues, and/or shake, other have it. When I first bought the truck and maybe up to about 5k miles I didn't notice it. But now its very noticeable. And its not just the center, you can feel the vibration all over. I can hear the zippers on my bag rattle in the backseat too. It's just these $45k trucks shouldn't have these "normal" issues.

Posted
On ‎10‎/‎18‎/‎2017 at 6:31 AM, JK29 said:

Hey Buckem,

 

Mine has the RPM "flutter" as well every time the truck shudders. It swings about 150-200 RPM each shutter. My truck is 100% stock. It also goes away on deceleration.

Took truck back in for vibration and they listened to me this time.  Test drove again and felt vibration. Doing a tranny flush and possibly replacing torque converter per GM recommendation.  Also got shim kit installed for drive seat movement, tranny TCM update, airbag/seatbelt recall taken care of and front end alignment.

  • Like 2
Posted
On 10/27/2017 at 5:10 PM, Dmf10e said:

Yeah I thought about that. Just seems hit or miss on here. Some people don't have the issues, and/or shake, other have it. When I first bought the truck and maybe up to about 5k miles I didn't notice it. But now its very noticeable. And its not just the center, you can feel the vibration all over. I can hear the zippers on my bag rattle in the backseat too. It's just these $45k trucks shouldn't have these "normal" issues.

Thats what I have too, and it drives me nuts. all the zippers from my gym bag, laptop bag, any tools in the back, sounds like a drunk 2 year old concert. not to mention if i do not have a passenger, the seat belt metal tab constantly rattles against the side pillar. Thought about putting 3m velcro (soft side) there so prohibit any additional rattles. 

Posted
On 10/17/2017 at 9:43 AM, Patriot78 said:

Sorry should be specified, it's a 6 speed, I have a range afm  module so I can try and see if that makes a difference but I'm pretty sure when I was using it before it made no difference 

I have a 6 speed and it still happens when I have my afm disabler in. Shifting is a little better too. Its a toss up for me for which i rather have an issue with over the other. haha. I'd like both to be fixed since its a $45k truck. Not normal!!

Posted (edited)

Been following this thread as I've had a shaker of a Denali for over a year.  Replaced most of the tires to RFB them which made it better, but then on first tire rotation, problem came back.  It spent all last week at the dealership.  GM ended up swapping out the Goodyear Eagles that came on it with some Bridgestones and the problem seems better on first drive.  Fingers crossed it stays that way, but I gotta wonder if the different tire is a different durometer or something and just masking another problem.

Edited by UWSkier
Posted (edited)

has anyone replaced their Torque converter themselves? I am out of warranty and thinking of replacing the TC as well as the axles from Yukon and Bilstien 5100 shocks. 

 

If you did replace your TC, what one did you use and did it end up helping? I have lots of other issues with RPM surges that im hoping this could eliminate a few issues

 

 

Edited by EFLine

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Latest Articles

  • Posts

    • Monday looks like a good day for the dealer to test an ac issue. Hopefully it all turns out good.
    • Paid $2.72 for E85 today.
    • Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • 2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...