Misfire Cylinder #7 P0307 W/ White Smoke

[Cwildman]

Right on, I wonder what a 6.2 engine is worth, and can it be used with the same trans/gearing. Exhaust is also bigger in the 6.2. could be an expensive swap. Either way I'm curious what you end up doing.

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[wyattkb]

Finally got the motor out and pulled the head off today. Intake lifter failed on cylinder 7, just fell apart when I pulled it out. I got lucky and it didn't rotate in the tray and take the cam out. I don't know if the dealer was trying to pull a fast one on me but I found no metal debris in the oil or filter after cutting it open. Although the intake manifold did have some dirt inside of it the heads were clean, cylinders clean, nothing other than the failed lifter.

 

Plan now is to do a cam and DOD delete.

 

I am still really upset at the the dealership for turning me away when this was clearly a failure on their part.

[Rick B]

I had the same issue with cylinder #7, Dealer diagnostics and inspection show faulted AFM lifter and exhaust valve.

$2300.00 repair.

[Skeeterhawk]

You guys aren't screaming at gm loud enough. GM knows they are having lifter problems and not just with the AFM lifter.

They should give some assist on the repairs.

They are still having lifter problems on the new trucks.

They are doing away with AFM for 2022 motors.

I won't be buying one. I'm leaning towards Dodge and may look at Ford too.

[Lawman86]

On 6/25/2020 at 4:09 PM, wyattkb said:

Finally got the motor out and pulled the head off today. Intake lifter failed on cylinder 7, just fell apart when I pulled it out. I got lucky and it didn't rotate in the tray and take the cam out. I don't know if the dealer was trying to pull a fast one on me but I found no metal debris in the oil or filter after cutting it open. Although the intake manifold did have some dirt inside of it the heads were clean, cylinders clean, nothing other than the failed lifter.

 

Plan now is to do a cam and DOD delete.

 

I am still really upset at the the dealership for turning me away when this was clearly a failure on their part.

110% don’t believe the dealer, I know the gimmick. I was a service manager/shop manager for a very large International dealership and that’s how they make money off folks. Techs know how to make it look like it’s completely shot, the manager is usually a smooth talker too. I’m going to get mine done before long. I figured I’ll either do it myself or pay to get it done. Not because I haven’t t done it 100 times, my back hasn’t been the same since I broke it, so bending over and grabbing heads isn’t as easy as it was before. Hopefully you got it all going by the time you get this post

[Supreme Pizza]

I had the exact same symptoms. Sometimes white smoke sometimes not. Sometimes blue smoke. #7 intake lifter collapse.

 

Pulled the valve cover to confirm.

 

Tried the "unstick" trick on the lifter, but no luck. (hammering on the lifter through the oil port under the valley cover).

 

Pulled the head.

 

$43 for the lifter. $60 in gaskets. $12 new coolant. $100 AFM disbaler.

 

Maybe 4 hours labor, maybe 6 including cleaning of parts, drinking beers, etc.

 

It sucks to have to do it, but I would not mind doing again if I needed to.

 

 

 

I only pulled one head, but aside from that - this is about how far I have been into my motor, if you are including the O-ring on the pickup tube repair that I did.