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..