Dreaded Cylinder 4 misfire

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Bagherra

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Got a 2016 Denali 4WD with 107K miles, oil changes done religiously max every 6000 miles with Mobil 1 0W-20. Not my daily driver...mostly weekend runs around town..
Went to pick up daughter and noticed a stumbling with the engine, CEL was flashing and TRACTION CONTROL light was on. Pulled back in driveway and pulled CEL code, P0304. Replaced plug and wire and moved ignition coils. Same thing....then smoke started to come from exhaust.

From what i've read on this forum, appreaded to be a stuck lifter. Got truck towed to dealer and waiting their diagnosis. Got the extended warranty and praying like hell they will cover repair.

I keep hearing about AFM delete. What exactly does that involve?

Thanx in advance y'all!!
 

swathdiver

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The dealer cannot do an AFM delete. An AFM delete replaces the De-Ac lifters with standard ones along with the camshaft and a flat plate valley cover replaces the VLOM along with new bolts and gaskets and fluids and such. It also requires that the computer be modified to turn off AFM and be tuned for the new camshaft.

Keep us posted on what the dealer says. It ought to be covered whatever it is. AFM in your truck is very reliable but like anything, things wear out.
 
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Bagherra

Bagherra

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Just heard from mechanic, he says cylinder 4 is dead and they need to do a teardown to determine why. Maybe from there he can determine if it was lifter failure.... From there they will contact the warranty company to work shit out... He thinks a new engine...

Thanx for info about the AFM delete!

Praying for good news!!!
 

SpyShops212

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Dealer called yesterday....cylinder 4 lifter collasped. Waiting for warranty company to ok repairs...$5100 is what i was told....
I just had the same issue and they replace lifters 4 & 6 also they used an updated vlom and change all the gaskets and whatnot. Make sure they change lifter 4 & 6 and the vlom with the updated part, don't settle for less. You might be able to contact GM and ask for some assistance. You should pay for the oil pressure sensor, spark plugs, and screen to be replaced since they will be in there anyway.
 

Roll On

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Good luck with your ordeal, at least they found the problem. My guess is that the warranty will cover a good portion of it; I had some warranty issues and I had to pay $100, it was worth it for the amount of stuff that they did.
 
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Bagherra

Bagherra

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Here's the latest and greatest....

Warranty assholes refused to cover the costs because i didnt have my oil changed at an "authorized repair facility". The receipts i provided wasnt enough....
Went to dealer to see exactly what happened...lifter collasped at cylinder 4 with broken pushrod. No damage to camshaft, but $5400 to fix. $2300 in parts and $2900 in labor...
 

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Bagherra

Bagherra

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They called me last night and told me my truck was ready. Will be picking up when i get off work....
 

Blackcar

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Here's the latest and greatest....

Warranty assholes refused to cover the costs because i didnt have my oil changed at an "authorized repair facility". The receipts i provided wasnt enough....
Went to dealer to see exactly what happened...lifter collasped at cylinder 4 with broken pushrod. No damage to camshaft, but $5400 to fix. $2300 in parts and $2900 in labor...
Those parts look like oil been changed to me no sludge oil won't keep a push rod from bending that's mechanical and not from no oil changes.
There is TSB on this problem and not from oil changes. I would be disputing this.
Here any engineers view on bent push rods
Here's the latest and greatest....

Warranty assholes refused to cover the costs because i didnt have my oil changed at an "authorized repair facility". The receipts i provided wasnt enough....
Went to dealer to see exactly what happened...lifter collasped at cylinder 4 with broken pushrod. No damage to camshaft, but $5400 to fix. $2300 in parts and $2900 in labor...
 
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