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I thought I would share one of the things I've been to in the last few months. I have a 2007 Avalanche that I purchased new. It now has 209,000 miles on it. I'm sure that some of you know that the Active Fuel Management can be a real problem on these engines. I'm a dedicated oil changer on my engines and I never had a problem until the truck reached 200,000 miles. Original everything in the drive train. So with my engine running great at that mileage one day and then...........BAM, a new noise. A knock that the dealer said was a rod bearing out. I did not believe that because the oil pressure never dropped and I had taken excellent care of the engine. I used a mechanics stethoscope and found the noise to be greatest when I placed the probe on the exhaust manifold at the head between cylinder #1 and #3. So I thought it was possibly a lifter, but the engine was still running smooth, just with a new knock.

Anyway, one of the bad things that happen to these engines is the induction of a lot of oil into the intake manifold via the crankcase ventilation from the drivers side valve cover. GM even brought out a redesigned cover which helped some. There's a lot more to it but too much to address here. There are two different types of lifters in these engines with four of the eight cylinders using a special lifter that are really a lifter in a lifter. When the computer calls for 4 of the cylinders to shut down the special lifters deactivate the valves for those cylinders. All done hydraulically via solenoid valves in the valley cover.

Some folks were using quarts of oil in under 1,000 miles. Mine was not using that much but was using more than it should. So the fix is to eliminate the Active Fuel Management by taking out the special lifters and replacing them with standard stock lifters. That also meant changing out the valley cover and turning off the AFM in the computer.

So with my new knock and the desire to eliminate the AFM I decided to remove the engine and rebuild it. This is not something I wanted to do as I'm 75 years old now and I really thought I was done doing these types of things, but I didn't want to spend 5 or 6 thousand dollars at a dealer and not know everything they had done incorrectly. This all cost me around $3,000 to do it myself, but it also costs me 3 weeks without my truck. One week removal, one week at the machine shop, and one week back together.

So here is what was causing the knock. #3 piston skirt broke. All of the pieces were in the bottom of the oil pan.
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Here's a removal progress shot.
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Heads off. Now I can get to those miserable bell housing bolts.
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Engine coming out. That load leveler was a PITA and not worth the money. The reason is the engine sits back far enough under the cowl which makes it difficult to use it effectively because of lack of room over the engine.
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Short block back from the machine shop. I had them assemble the short block for me. They bored the cylinders, replaced all bearings, new pistons, reground and polished the crank. I installed a new cam from Cam Motion. It's a little more cam than stock and the grind is meant for trucks. The new cam meant that I had to get my truck tuned in order to take advantage of the increase in power.
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Assembly progress shot. The new timing gear and chain installed. See that orange engine stand in the background? That's one I made back in the 60's and of course it wouldn't work so I had to buy a new one from O'Reillys. Hopefully, I'll never need to use it again.
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Progress shot. New oil pump installed.
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Progress shot. Windage tray and pickup tube installed.
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Progress shot. Front cover installed with new oi seal. I made an alignment tool on my lathe to make sure the seal was centered correctly on the crank nose.
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Motor mounts and A/C compressor mount installed.
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Reworked heads ready to be installed. I replaced the valve springs with some that were recommended for the cam change.
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Engine back in the truck and the heads installed. Believe me, at this point, I had been under the truck and in the engine by A LOT of times! But I'm getting back in shape with all of the moving around.
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Intake manifold installed. At last!
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Here is a oil precharge tool that I made from PVC pipe. These engines are not like the older engines that you precharge using a drill and a shaft to drive the pan mounted oil pump. I tried my best to get the new pump to suck the oil up and charge the oil galleries but it just wouldn't do it. I filled this PVC tube with 5 quarts of oil and used about 20lbs air pressure to fill the galleries. It worked great.
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This is a broken head bolt!!!! GM uses "Torque to Yield" bolts in a lot of places now and they SUCK! I chose to put the heads on after the short block was installed because it's a lot easier to get to those bell housing bolts as mentioned before. That meant that the cheap angle (degrees) meter that you can use to measure the amount of twist you put on the head bolts would be a bear to use when at the rear of the heads. I chose to purchase a new electronic torque/angle wrench to tighten the bolts. I thought that would be easy.................wrong! While tightening the bolts I could literally feel them stretching. Not a very comfortable feeling knowing from past experience that breakage is sure to come at some point. Well, I made it to the next to last head bolt and one broke. Luckily it was at the front of the passenger side head. Believe me there was a lot of interesting words being spoken and rather loudly too! I called the machine shop and asked the man about removing the bolt and he gave me an excellent tip. He told me to use a carbide burr with an oval tip so I could center the bit and create a crater in the end of the broken bolt which was down about 3/4" below the surface of the block. That made a place where the drill could center its self. I tried a left hand drill bit but it wouldn't grab and turn out the broken bolt because the bolt had loctite on the threads and it was pretty tight in the hole. I drilled far enough to be able to use an easy out type removal tool and I finally did get the bolt out. But I did decide to remove both heads and purchase a set of ARP head bolts that just torque in like any ordinary bolt. Much easier.
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So it's all done now and running great. It did take three trips back to the tuner to get the PCM (power control module) tweaked to my liking.
 

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Very nice job!:good2:

I'm assuming you bought new head bolts initially?? I know from experience to never, ever reuse head bolts.
 

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Interesting story jimfrits. Are you good for another 200,000 now?
 

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Discussion Starter #5
Interesting story jimfrits. Are you good for another 200,000 now?

I'm hoping for 300,00 now. A friend of mine sells Schaeffer oil and I'm running that now. That is some great stuff. My engine definitely became quieter when I put that in.
 

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That was quite an undertaking! :good2:

I have heard the rings on deactivated cylinder(s) stick and then oil usage starts. Were the rings stuck on the broken piston?

Most just have the AFM tuned out, but can still end up with oil burning. :dunno: :banghead:

I am glad my Silverado does NOT have AFM. 2011 6.2L

Did you consider a "crate engine" replacement?
 

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We have a 2011 with the 6.2l as well but it does have AFM. There was an engine revision I think in 2010 to address some of the issues that the earlier engines had. I agree that most people that remove it do it through a tune but in this case you tore apart the engine anyhow. The piston skit breaking is pretty common. I am surprised you made it to 200K.

I know I looked into these issues a while back and I though part of the problem with AFM is kind of a two fold thing. They use low tension piston rings to help out with MPGs. They are fine but are designed to have cylinder pressure from the power stroke to help seat the rings and keep oil consumption in check. When the cylinders deactivate there isn't any cylinder pressure because the lifter in a lifter is holding the valves open.
 

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Discussion Starter #9 (Edited)
Man, I would have just ran it until it blew up. That's some serious coin to drop on an 11 year old truck/SUV...
Two things made me do this. I simply can't afford an absurdly priced new truck and this truck is in excellent condition. The truck literally has one small door ding on the right rear passenger side door. How did I do this? I always park away from the "parking lot demolition derby". Absolutely no rust....NONE! The truck is always garaged when I'm home from the day I purchased it. It performs equal to the day it was built. The transmission has had 3 flushes since new and is performing perfectly. The front end was rebuilt by me last fall with new hubs, all four A-arms ball joints, and all tie rod ends. Oh, and new shocks all around. The interior is excellent except for a small 3" tear on the drivers seat from sliding in and out, but I already have a new OEM seat cover waiting to be installed and I'll buy a new foam pad from The Seat Shop when I replace that. I love this truck and I've had a lot of different trucks since I started buying them back in 1976. Avalanches are great trucks. I can carry 4x8 sheets of plywood in the back and still close the gate.

Here is one of my all time favorite trucks I had. A 2002 2500HD with a 6.0L engine with 4.10 gears. A used truck like this that is in excellent condition will cost you plenty. The prices I've seen are very high and above book. I sold this truck to buy the Avalanche. At the time, my first wife had Alzheimers and was not driving any more and I needed a vehicle that could serve as a car and a truck. The Avalanche fit that perfectly. Just the other day I was looking at prices for a 2002 2500HD and they were around $10,000 for a decent one. I even saw one listed for $19,000.
2002ChevySideView.jpg
 

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Discussion Starter #10
We have a 2011 with the 6.2l as well but it does have AFM. There was an engine revision I think in 2010 to address some of the issues that the earlier engines had. I agree that most people that remove it do it through a tune but in this case you tore apart the engine anyhow. The piston skit breaking is pretty common. I am surprised you made it to 200K.

I know I looked into these issues a while back and I though part of the problem with AFM is kind of a two fold thing. They use low tension piston rings to help out with MPGs. They are fine but are designed to have cylinder pressure from the power stroke to help seat the rings and keep oil consumption in check. When the cylinders deactivate there isn't any cylinder pressure because the lifter in a lifter is holding the valves open.
I'm not surprised about the piston skirt problem. These engines had a lot of piston slap until they warmed up. I did a lot of research prior to doing the AFM delete. A lot of good information in various forums and on YouTube.
 

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Discussion Starter #11 (Edited)
That was quite an undertaking! :good2:

I have heard the rings on deactivated cylinder(s) stick and then oil usage starts. Were the rings stuck on the broken piston?

Most just have the AFM tuned out, but can still end up with oil burning. :dunno: :banghead:

I am glad my Silverado does NOT have AFM. 2011 6.2L

Did you consider a "crate engine" replacement?
I did look at crate engines, but they are VERY expensive. The term "crate" means that it's a brand new complete never run engine. The terms, rebuilt and remanufactured both have different meanings. Rebuilt means that they disassemble and only replace parts that are worn out beyond specs. Remanufactured engines are better than rebuilt, but who trust these guys to do it right? Not me. I knew what I had with this engine and was very confident it was a good candidate to rebuild. The only original moving parts used again were the crank, rods and valves.

I'm happy with this engine and still can get over 21 mpg on the highway when I drive like a normal person and under good conditions.
 

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Man, I would have just ran it until it blew up. That's some serious coin to drop on an 11 year old truck/SUV...
As compared to A) $40k plus on a new one and B) there not being a current truck anything like it in the GM lineup?

I agree that it's a lot. But, if everything else is still in good to very good working order, little or no rust, and it's paid for - $3k is a cheap way to bring it back.

:thumbup1gif:
 

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Man, I would have just ran it until it blew up. That's some serious coin to drop on an 11 year old truck/SUV...
$3k is not that much. Have you seen the re-sale on used trucks lately? I have been shopping for a used truck for my son and I am looking at trucks from 1996-2005 or so and even the old ones with gen 1 small blocks are bringing what I consider a big price in the 4-7k range. In my mind he is smart to rebuild the engine in his truck even if it is 11 years old. That 5.3 will be good for another 200k. A replacement new truck is crazy expensive. He would be lucky to get a new 1/2 ton crew cab for under 40K (if he went with 2 wheel drive then probably). So $3k vs 40k for a new one.....besides the OP is 75 years old, I am sure he doesn't want a new car payment at his age.

I have oil use problems in my 2013 suburban and it's at 98k. I thinking it's the AFM as well. Your thread is inspiring to make me want to fix mine. Just need to finish my shop first....so I have room to work. His shop looks really nice and clean. :bigthumb:
 

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In my area the every day drivers start to rust between 10-15 years. That would be my ONLY reason RUST, not to fix it.
 

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Here are photos of the truck taken today. This is one reason I thought it was worth fixing.

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Here is the single door ding (dent) that the truck has at the moment........
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If you like it, that's all that matters. Personally, I'd rather see it being used for what it was intended than see it in a salvage yard in pieces. I did a lot of this when I was younger and probably to vehicles others didn't think worthy of my time or money.
 

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Truck is in excellent shape! Well worth the time and money to fix. Your Avalanche body style was the very best. The body style with the plastic all over the sides was ridiculous to say the least. My .02 of course.
 
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