Plugs dirty after 800 miles

[bdbull]

Just finished changing the intake manifold gasket. Cranked it up to see if it was any better. Still rumbling and stumbling, although maybe not quite as bad. Pulled a P0102 and P0306 out of pending codes. The P0102 went away on the next run. I cleaned the MAF while I had everything apart so hopefully the P0102 was just a remnant of that. However the P0306 was still there so I'll look into plug #6 once the engine cools down.

 

[bdbull]

Just sort of using this thread as a log of what I've done so far.

Pulled the plug and it appears to be fine. Swapped the coil packs between #4 and #6 and the misfire stayed on cylinder 6. I should have swapped the plugs too, but figured it looked ok. I'll swap them today and see if the misfire stays on #6. I think after that, next move is to pull the valve cover and check for a stuck or collapsed lifter. I'm hesitant about that given the issues I've had with the valve cover bolts and also because I'm not hearing that ticking/knocking noise that usually comes with a stuck or collapsed lifter.

 

[bdbull]

Collapsed lifter!!! Took the valve cover off tonight and cylinder #6 has a collapsed lifter. The rocker arm is loose just like all the videos I've seen. I think my plan is to order the tool from CrazedPerformanceRepair to try to get it unstuck. Then perform his suggested mods to the VLOM. Finally I'll send off the ECM to LT1swap.com to get the AFM tuned out of it. Hopefully that will get me back on the road for another 200k miles.

 

[SNES Avalanche]

Collapsed lifter!!! Took the valve cover off tonight and cylinder #6 has a collapsed lifter. The rocker arm is loose just like all the videos I've seen. I think my plan is to order the tool from CrazedPerformanceReview to try to get it unstuck. Then perform his suggested mods to the VLOM. Finally I'll send off the ECM to LT1swap.com to get the AFM tuned out of it. Hopefully that will get me back on the road for another 200k miles.

Glad you got to the bottom of this!

 

[bdbull]

Well, as usual things haven't gone according to plan. I got the tool to free the lifter but haven't been able to get it free yet. Looks like I'm gonna have to remove the head to get at it. However, since the head will have to be pulled to get the bad lifter out, I figure I might as well go ahead and do a full AFM delete while things are torn apart. I've already talked to a local shop about doing the work for me as it's a little over my head. I'm planning on ordering a kit from Texas Speed and Performance as they seem to be the biggest player in that space. Hopefully we'll eventually get to a good place with this.

Was really hoping I could be back on the road with just the lifter tool trick and a tune, but I guess the car gods have other plans.

 

[Geotrash]

With that many miles on that engine, I'd be inclined to just pull the head and install all new lifters (AFM and regular) and trays on that side only, then have the AFM tuned out. Unless you're looking for more performance....

It will save you a bunch of money and you'll probably never have to touch it again because the primary failure mode of those lifters won't occur again with the system tuned out.

 

[bdbull]

Yeah, that would have been cheaper, but I figured the labor would be almost the same so I might as well fully get rid of the AFM while it's opened up. And with my luck lately the failed lifter probably damaged the cam shaft too so I'd need to replace that. Hell with my luck, I'll get it back all fixed up and then get T-***** pulling out of the shop.

 

[bdbull]

Of course I had to give it one more try before I started putting everything back together. What do you know, the lifter freed up and shot the pushrod right out like it's supposed to. So, in theory my truck should be drivable now once I get my computer back. However, the damage that the tool took when the lifter finally freed up has me a little worried. I'm guessing there's a little piece of metal floating around in there somewhere now. My plan was to put a bottle of Rislone in it and let it idle for a little while and then change the oil anyway. Hopefully whatever came off the tool will get caught by the filter. AFM delete kit is scheduled to be delivered Friday and I talked to the shop about bringing it in Monday morning.

 

[Geotrash]

I figured the labor would be almost the same so I might as well fully get rid of the AFM while it's opened up.

The labor will be more than double. Glad you got it freed up though!

 

[SNES Avalanche]

Of course I had to give it one more try before I started putting everything back together. What do you know, the lifter freed up and shot the pushrod right out like it's supposed to. So, in theory my truck should be drivable now once I get my computer back. However, the damage that the tool took when the lifter finally freed up has me a little worried. I'm guessing there's a little piece of metal floating around in there somewhere now. My plan was to put a bottle of Rislone in it and let it idle for a little while and then change the oil anyway. Hopefully whatever came off the tool will get caught by the filter. AFM delete kit is scheduled to be delivered Friday and I talked to the shop about bringing it in Monday morning.

Keep us updated!

 

[bdbull]

So just wanted to update this thread with my progress (or not progress).

Truck has been running great since I got the lifter unstuck. I would almost say it's been running better than it has in years. However, I still wanted to get the parts swapped out so it is a full AFM delete engine. Dropped it off at the shop yesterday to have the work done with the Texas Speed kit that I ordered. They just called me with the estimate: $4000!!! I was not expecting it to be that much. I obviously haven't done the work myself, but I've watched it done a number of times on Youtube and I was not expecting that. I almost did it myself originally, but I'm hesitant on the cam work since I've never touched that before. But now, I may be doing it myself. I told him to just cancel it because I wasn't expecting that. Guess I'll be doing some major Youtube watching so I can figure out how to do it myself at some point.

 

[Geotrash]

So just wanted to update this thread with my progress (or not progress).

Truck has been running great since I got the lifter unstuck. I would almost say it's been running better than it has in years. However, I still wanted to get the parts swapped out so it is a full AFM delete engine. Dropped it off at the shop yesterday to have the work done with the Texas Speed kit that I ordered. They just called me with the estimate: $4000!!! I was not expecting it to be that much. I obviously haven't done the work myself, but I've watched it done a number of times on Youtube and I was not expecting that. I almost did it myself originally, but I'm hesitant on the cam work since I've never touched that before. But now, I may be doing it myself. I told him to just cancel it because I wasn't expecting that. Guess I'll be doing some major Youtube watching so I can figure out how to do it myself at some point.

If I did it myself, you can too. I don't have a fancy lift, but I do have good jack stands, a garage, and a decent set of tools. I also enjoyed the work and knowing that the job was being done right. Good thing because I had to do it 3 times due to bad lifter trays (cheap knock-offs sold to me as new OEM by a reputable cam manufacturer) that I didn't figure out until after the 2nd cam failed.

If you decide to tackle it, you'll get good support here.

 

[bdbull]

If I did it myself, you can too. I don't have a fancy lift, but I do have good jack stands, a garage, and a decent set of tools. I also enjoyed the work and knowing that the job was being done right. Good thing because I had to do it 3 times due to bad lifter trays (cheap knock-offs sold to me as new OEM by a reputable cam manufacturer) that I didn't figure out until after the 2nd cam failed.

If you decide to tackle it, you'll get good support here.

Did you use a manual to do it? Youtube? How long did it take you? Did you have to drop the oil pan? I replaced the oil pan gasket myself a few months ago and that was not a fun job. Nearly lost several fingers when the front diff dropped off the transmission jack I was using to get it back in. I feel like I could do it myself, but I'm afraid of Murphy's Law.

 

[Geotrash]

Did you use a manual to do it? Youtube? How long did it take you? Did you have to drop the oil pan? I replaced the oil pan gasket myself a few months ago and that was not a fun job. Nearly lost several fingers when the front diff dropped off the transmission jack I was using to get it back in. I feel like I could do it myself, but I'm afraid of Murphy's Law.

I used a combination of the Haynes manual, alldatadiy, YouTube videos for specific things like changing the oil pump, and advice from people here. You can do the cam and lifter swap in a weekend if you don’t have to replace the oil pump. I dropped the oil pan but you don’t need to if not replacing the oil pump. Here is the capstone post from my thread:
Post in thread '2012 Yukon XL Denali 6.2L Cam Swap Thread'
https://www.tahoeyukonforum.com/thr...nali-6-2l-cam-swap-thread.121671/post-1616690

 

[FasterBass]

Question for @bdbull was your idle pre-getting-lifter-unstuck bad whether the truck was warmed up or not? Had similar looking plugs when I changed mine, and only my hot idle is a bit lumpy.

 

[bdbull]

Question for @bdbull was your idle pre-getting-lifter-unstuck bad whether the truck was warmed up or not? Had similar looking plugs when I changed mine, and only my hot idle is a bit lumpy.

Not sure if by "pre-getting-lifter-unstuck" you mean when the lifter was actually stuck or before it even got stuck. Before it got stuck, it was a rough idle all the time no matter how warm the engine was, and it was that way for a long time. Once the lifter got stuck, I didn't drive it at all bc the dash was lit up like a Christmas tree and it sounded horrible. Only drove it the few miles back to my house from where it got stuck, and then it sat in the garage for 3 weeks while I tinkered on it.
Since getting the lifter unstuck, it purrs like a damn kitten. But keep in mind, I also had the AFM deleted from the computer and did the VLOM mod recommended by CrazedPerformanceRepair on Youtube. Really starting to think the AFM might have been the root cause of the rough idle to begin with.

 

[FasterBass]

@bdbull thanks for the reply. I have already deleted AFM through Blackbear and had not heard of VLOM. Will take a look - I certainly don't have a TERRIBLE idle but ocd is kicking in and want it to be correct.