AFM disable or lifter issue 2012 PPV TAHOE

[aye_rod]

Whatsup everyone. New here and reading a lot of other threads and curious to know if anyone has had the same issue. I have a 2012 Tahoe PPV with like 113k miles.

Driving on the highway for 8 hours straight at like 70mph no problem. I go through a town and get into a red light. I start hearing a ticking noise and the engine begins to stutter as I accelerate at the green light. I’m pressing the gas pretty hard but not going anywhere. The vehicle is stuttering so I pull over and turn off engine. A few minutes later, I turn it back on and weird noise is back and the smell of like burning oil/rubber something is smelling out the exhaust and engine area. Turn off again and towed home.

Next day I turn the engine on and it starts perfectly fine, no stuttering or smell. I hit the gas while in park to see and it rolls fine for about 10 seconds until the jerking and exhaust pops (sounding like I was at a drag race lol). The 0300 code is what I get for the check engine light and misfiring on #6 a lot.

I don’t hear the notorious “ticking” noise for lifter issues like I’ve been reading during the cold start. Only starts acting up when I’m hitting the gas. Wondering if I just get the AFM disabler and it will pass? Do lifters happen to malfunction and go back to normal? I put full synthetic oil changes, use fuel injector cleaner regularly. I feel like it should’ve happened on the highway during the 8 hour trip if it was a lifter issue. Any help, helps

 

[gooffeyguy]

Have you checked the spark plug/plug wire on that cylinder? Could also be the coil pack.

If you want to narrow the problem down to if it's the AFM or not, the system can be disabled when running the trans in manual mode. Just select the highest gear and drive it like normal.

 

[j91z28d1]

yeah. this doesn't feel like afm issue. afm doesn't come on in neutral or when still cold. this sounds more like it's missing from either spark or fuel and the ticking is most likely a broken exhaust manifold bolt and when it's running badly your hear the exhaust leak worse than normal.

but if you want to know forsure, a compression test will tell you and you can see if the plugs are fouled while you're there.

 

[petethepug]

We’re you getting down to the bottom of the gas tank? Pocket of condensation or a carbon pellets that got out of the carbon canister?

 

[Dustin Jackson]

The smell part is interesting have you looked around the engine bay to see if anything burned up or a belt?

 

[rdezs]

Just having the strange smell would seem to indicate that something other than the lifters. I be checking the wiring harness for anything melted. Also for any oil leaks saturating any part of the harness. Such as the camshaft or crankshaft sensor. While you're at it make sure the two large plugs on the left side of the transmission are dry as well. Wipe the inside of the tailpipe with a paper towel and smell.... if there's evidence of coolant or oil you found your problem. Those two contaminants will seep through the exhaust at various connections and you'll smell it in the cabin. That would be internal engine damage of course.

 

[ccbaugh]

Whatsup everyone. New here and reading a lot of other threads and curious to know if anyone has had the same issue. I have a 2012 Tahoe PPV with like 113k miles.

Driving on the highway for 8 hours straight at like 70mph no problem. I go through a town and get into a red light. I start hearing a ticking noise and the engine begins to stutter as I accelerate at the green light. I’m pressing the gas pretty hard but not going anywhere. The vehicle is stuttering so I pull over and turn off engine. A few minutes later, I turn it back on and weird noise is back and the smell of like burning oil/rubber something is smelling out the exhaust and engine area. Turn off again and towed home.

Next day I turn the engine on and it starts perfectly fine, no stuttering or smell. I hit the gas while in park to see and it rolls fine for about 10 seconds until the jerking and exhaust pops (sounding like I was at a drag race lol). The 0300 code is what I get for the check engine light and misfiring on #6 a lot.

I don’t hear the notorious “ticking” noise for lifter issues like I’ve been reading during the cold start. Only starts acting up when I’m hitting the gas. Wondering if I just get the AFM disabler and it will pass? Do lifters happen to malfunction and go back to normal? I put full synthetic oil changes, use fuel injector cleaner regularly. I feel like it should’ve happened on the highway during the 8 hour trip if it was a lifter issue. Any help, helps

A lifter losing prime will cause this issue. Sometimes they will pump up and then stop. When that happens, the engine cannot complete combustion and that's where you get your smell from the exhaust. Sometimes a lifter will fail, and you never get a ticking sound. Just a misfire. A compression test won't show anything sometimes if the lifter fails and the valves remain closed. On the highway the oil pressure is higher than idle so the lifter can stay primed better than it can at idle.

 

[hillstrubl]

I'm seeing some posts on other posts (Reddit) about how software only AFM (Range, etc) only exacerbates lifter failure?

 

[donjetman]

I'm seeing some posts on other posts (Reddit) about how software only AFM (Range, etc) only exacerbates lifter failure?

Its a bandaid for sure

 

[mikez71]

Disabling the lifters is a good step and shouldn't make anything worse. (unless you re-activate AFM)
The actuating part won't get fresh oil anymore, but those parts should never move again..

 

[Marky Dissod]

I'm seeing some posts on other posts (Reddit) about how software only AFM (Range, etc) only exacerbates lifter failure?

If your tennis elbow is REALLY bad, you may need to do much more than just stop playing tennis.
Still a great idea to stop playing tennis though, even if there's much more to be done.

Engine Half@$$ lifters are the real problem, though.
They are simply not as durable / robust as simpler lifters. Simpler lifters often outlast the engine they came in.
Engine Half@$$ lifters, not so much.

To keep Engine Half@$$ lifters as long as their weak@$$ materials and schidty specs will let them,
change oil as often as reasonably possible, and avoid wide open throttle and high RpMs.

Bandages sports wrap & physical therapy are not enough once a necessary surgery has been put off for too long.
Too many people avoid disabling Engine Half@$$ (or Engine Confusion) at the first possible opportunity -
they wait until or even after it starts showing symptoms.

By that time, major engine surgery to remove ALL the Engine Half@$$ bits is what's necessary.
Truth is, sooner or later, most of these engines will need to have all that lazy cylinder hardware replaced,
with REAL V8 parts.

 

[R467X]

I ran an AFM disabler for many years before doing an AFM and VVT delete a number of months back.

The disabler is, in fact, a bandaid, only prolonging the inevitable lifter collapse. You keep driving like that and may find yourself paying for a rebuilt / new engine.

When I'd unplug my AFM disabler and AFM came back on, my engine would studder and make all sorts of weird noises, when switching back and forth from 4 to 8 cylinders.

It all boils down to this - are you going to keep your rig? Or are you going to get rid of it soon? If you choose keep, then do an AFM delete.

 

[j91z28d1]

I ran an AFM disabler for many years before doing an AFM and VVT delete a number of months back.

The disabler is, in fact, a bandaid, only prolonging the inevitable lifter collapse. You keep driving like that and may find yourself paying for a rebuilt / new engine.

When I'd unplug my AFM disabler and AFM came back on, my engine would studder and make all sorts of weird noises, when switching back and forth from 4 to 8 cylinders.

It all boils down to this - are you going to keep your rig? Or are you going to get rid of it soon? If you choose keep, then do an AFM delete.

this is what makes the obd2 plug ins not great. once you stop using them they gunk up even worse than when being used and as you saw struggle to release.

short of removing the hardware, tuning it off in the tune itself so it never comes back on it a better idea.

I also like the idea of venting the oil passageway to the activation side too. but that's more involved

 

[MiniVini41]

Disabling the lifters is a good step and shouldn't make anything worse. (unless you re-activate AFM)
The actuating part won't get fresh oil anymore, but those parts should never move again..

+/- "unless I re-activate AFM" - If i disable AFM with an OBD2 Disabler... then 1x every 2 years for a few hours, i have to remove the Disabler to get smogged IN California... will this make it worse? How do people in California deal with AFM?

 

[mikez71]

Get it tuned out! It's cheaper (lt1swap.com), and better than a disabler.

AFM Delete

The very bottom of that page also has a couple links on ECM unplugging/removal.

Or do it yourself with HPTuners (costs more)

Passed smog here in sacramento, no problems.