GM Active Fuel Management Headache

We bought our 2008 Chevrolet Suburban LT in the summer of 2011. It had 74,000 miles on the clock and we paid about half of what it cost new. We lived in Florida at the time so it was perfect for us, a family of 5 plus a dog, to use on our trips back to Michigan to see our extended family. It has been a great family hauler, making our extended road trips across the country very comfortable, it made several trips to Michigan and Texas (our new home) without any trouble. That changed during our Christmas trip to Michigan in 2012. When we got to Michigan, it was cold, really cold. I noticed a lifter tick when the engine was started that I had never heard before, it diminished after the truck warmed up, so I assumed that the cold weather was causing the noise. Over the course of our 10 day visit, the tick became more pronounced, but would still diminish after the engine warmed up. Still convinced that the issue was cold weather related, we headed home for Texas. Somewhere in Kentucky the check engine light came on. So we pulled off at the next exit to check everything out, there was no smoke or smells, the oil level was good, (I had just changed it before the trip with Mobile 1 5w30), but there was the slight ticking sound that now never completely went away. Concerned by the tick, but determined not to spend a fortune to have a shop look at it on the road, we pressed on. The light stayed on, but no other issues developed, we made it home without incident.

After we unpacked and were settled, I put a code reader on the Suburban to find out what the check engine light was about. “Misfire on cylinder 6”, seemed like a strange error to me. The truck had never made any noise that sounded like a misfire to me, and it had plenty of power all the way through its rpm range. To trouble shoot, I swapped out the coils from the other cylinder bank, then the wires, then the plugs, each time clearing the code only to see it return to cylinder number 6.  Completely confused by this, I started looking online to see what a “Misfire on cylinder 6” meant for a GM 5.3 liter engine. What I found were numerous posts on multiple forums complaining about the Active Fuel Management (AFM) system on these engines. The posts talked about the AFM lifters failing or worse, on some aluminum blocked versions of these engines there can significant blow-by of oil past the piston rings, clogging the plugs. Since my 5.3 has an iron block, and the plugs I had swapped were clean, I focused on the lifters.

I needed to remove and inspect the lifters to determine what, if anything, was wrong. Since I did not have a manual, I decided to look online for any write-ups on 5.3 liter engine dis-assembly and assembly. While I did not find any good write-ups for the 5.3, I did find an excellent write-up on regarding head/cam swaps for Gen III LS1 engines here:

The LS1 is a different engine then the 5.3, but it’s based off a similar engine design, and it has the same dis-assembly and assembly procedures. Using the information from the link above, I removed the intake and heads, after removing the heads I could remove the lifters.

Head Off

Since the number 6 cylinder is were the trouble code pointed to, I started with the intake and exhaust lifters for that cylinder. Both of the lifter’s rollers were pitted, which means the rollers were slapping against the cam. Climbing on top of the engine, I used a flashlight to look down at the cam though the lifter opening. Sure enough, the cam was pitted as well. I had to remove all of the lifters and the cam, below is a picture of the damage:


So here I am with a busted GM engine with only 110,000 miles on the clock. Needless to say I was a bit peeved. I have owned GM cars for most of my life, and while the build quality of the body or interior could be spoty at times, the engines have always been bullet proof. I have several GM engines with well over 150,000 miles and still going strong. My old ’93 Yukon had a quarter million miles on it before the transmission quit, but the engine was still in great shape. I was really frustrated with this engine for breaking so soon, particularly with the fact the motor ran so well before the lifters failed.


After taking the motor apart,  I spent a lot of time researching AFM, how much replacement lifters cost, their likelihood of future failure, I decided I did not like AFM very much. AFM lifters cost $40 ea. and the cam costs $225. Total for the cam and a set of lifters was north of $500, and then there was no guaranty the Valve Lifter Oil Manifold (VLOM) was not the cause of the lifter failure in the first place. All in all the system is too complicated in my opinion, so I decided to remove AFM from my engine and be rid of its troubles for good.

I spent a lot of time researching how to remove AFM from the engine, more time than my wife would have liked since she had to drive our old ’94 Yukon (160,000 miles on it) in the mean time. An online search revealed many opinions, and options for removing the AFM, or performing a “DOD delete” on these engines. Below is what I did:

Replaced all of the lifters with LS7 lifters. (GM Part # 12499225)
Replaced the old AFM lifter trays with LS2 lifter trays (GM Part # 12595365)
Replaced the cam with cam for Hummer H3 Alpha 5.3 (non-DOD) (GM Part # 12625437)
Removed the VLOM and replaced it with an LS3 valley cover. (GM Part # 12599296)

All the parts, including new head bolts and all the gaskets, ended up costing about $650.


After everything was all put together this is what the engine sounded like:

I was pretty happy, but based on what I had read online this was not all there was to do. I had capped and taped the harness that ran to the VLOM. With it disconnected, the engine idled fine, but I decided to take it for a test drive to see what the computer would do without the VLOM installed.  Pulling out of the sub, the truck had no power, it would drive, but had absolutely no power. With the check engine light on, we turned around and drove the truck back home. I did not write the codes down, but there were several if I remember correctly, it was complaining about either missing or non-responsive VLOM solenoids, in response to these error codes the computer put the truck in “limp mode” which severely limited the power output of the engine.

After checking the codes, I used “HP Tuners” to program out AFM for the engine.

HP Tuners

This configures the computer to not use AFM or any of its components. After AFM was programmed out we took the truck for a second test ride, this time it ran great with no loss of power, and better yet it was always in V8 mode. No trouble codes returned.

In the time since AFM was removed I have been pleasantly surprised to see no reduction in fuel economy. The truck averaged 16 miles per gallon (we do mostly city driving) before the AFM system was removed, and it averages 16 mpg now. One has to wonder if the whole AFM gimmick is just a way for GM, in a controlled evaluation environment, to boost their truck mpg ratings for their CAFE numbers. As it certainly did not give us any real world mpg advantage, it just gave us a more fragile engine.  We’ve had over 27,000 trouble free miles since the rebuild was completed in January 2013. The Suburban has over 137,000 miles on it now, and without the specter of another AFM lifter failure in its future.

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What’s old is new again….. sort of.

When I was a teenager, I developed a keen interest in cycling. At fifteen I saw the movie “American Flyers”, I decided, if I was going to get in to racing, I had to have the bike that was in that movie. Now racing bikes aren’t cheap, even back then, so I got a summer job at a local grocery store and worked as many hours as they would let me so I could save up for that bike. At the end of the summer I have enough to put a good down payment on the bike for layaway at a bike shop, and spent the next several months, with help from my folks, paying it off. That bike was a 1985 Specialized Allez with Campagnolo components, it was a great bike, and I did well racing on it.

All of this brings me to my current topic, 10 years later, it almost seems like another life…. after College with a wife and full time job, I thought it would be a good idea to get a couple of mountain bikes for me and the missus. Since I had such an good experience with my first real bike, there was no other option in my mind then for me to get another Specialized bike. However, living with limited means, just staring my first real full time job the year before, I could not afford an M2 “Team” bike, or even a Stumpjumper, but I could get the next best thing, a 1995 Specialized Rockhopper FS A1 Comp.

I have had many miles in the saddle of this bike. I was still riding it 16 years later, without any complaints, it has been that good, I loved it!

Unfortunately, a few weeks ago after a 12 mile ride, I noticed 2 cracks in the head tube while I was wiping it down!

I was pretty bummed to say the least. I searched frantically online to see if there was a way to repair it, all I could find was that it could not be repaired, that it was to difficult to re-weld an aluminium frame and have it be safe to ride. However, I came across a few bike forums that had posts mentioning that Specialized had a lifetime warranty on their frames. So, I did some digging and found my original owner’s manual, and sure enough, it said that the frame had a lifetime warranty. I was more than a little sceptical that Specialized would warranty such an old frame.

I called the nearest Specialized dealer to me, and told them about what happened. They said to bring the bike in and they would take a look at it. When I brought it in, they took a quick look at the cracks and said that it was definitely a warranty issue. They said it would take a couple of weeks for Specialized to make a decision after they received all of the information from the shop. I called a couple of weeks later to check on Specialized’s answer, to my surprise, the shop had already received a replacement frame. However, to my initial disappointment, I was informed that the replacement frame was a Hardrock Pro. I must have sounded disappointed by the news, because the folks at the bike shop assured me that the replacement frame was as good as my old frame, but I remained skeptical and disappointed, as my recollection of the Hardrock is that it was/is at the bottom of Specialized’s line up. My disappointment quickly subsided though, when I saw the bike the following week.

It looks a bit retro! It’s made from Specialized’s A1 aluminium, the same as my old Rockhopper frame, and it’s a quarter pound lighter. I needed a new front derailleur due to cable routing changes on the new frame, and I had the shop tune it up, including a new chain and cables. Overall it was just $180 for the shop to perform the swap with the extra work thrown in. I guess after 16 years, bike technology has certainly improved, after several rides on my “new” bike, I can say that the new frame is as good or even better than the old one. I could have stayed hung up on the fact that it is not a Rockhopper, but I can honestly say that I am very happy with this bike.

Specialized has done right by me.


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Remembering/Restoring The Past

One day when I was fifteen, my family stopped to pay my grandparents a visit as we often did, while we were there I decided to rummage around in my grandparents shed. Inside the shed I came across an old metal fan sitting on a shelf. It looked like it had been there for a hundred years, it was caked in dirt and covered in a thick layer of dust. The fan was in pretty rough shape. What was left of the paint that I could see was very dark green in color, almost black in appearance. All of the screws and fan blades were made of brass, although I did not know it at the time as they were heavily corroded and dirty. The cloth covered electrical cord was frayed and it had several spots that had been “repaired” with tape. Overall it left a very poor impression, a candidate for the garbage dump I thought.

I brought it into the house to ask my grandfather about it. While we were talking I slowly came to the realization that my grandfather was rather fond of this fan, it had only been relegated to the shed because it was not safe to have around children, or pets. He told my the blades were brass, which I found hard to believe as they certainly did not look like brass to me. He went on, as some folks do, about how they don’t make things like they used to, and how much better this was than a modern fan. I questioned him on this, since the fan certainly did not look “better” than the nice shiny plastic fan they had in their house. He insisted it was better, and to make his point he declared, without having touched the fan for at least 10 years, that it still worked! As a typical fifteen year old, I responded, “No Way!”. He proceeded to plug the fan in and turn it on, to my amazement it started up with out hesitation. I sounded like a small airplane, and my grandfather was quick to remind me not to get anywhere near it, as it could “take your finger off”.

A couple of years later my grandfather passed away, and my family moved to accompany my grandmother. I asked my grandmother if I could clean up the old fan in the shed and she gave me permission to. I dove head long into the task. I took the fan apart, and as typical for a headstrong, impatient and foolish fifteen year old, I managed to break the gearbox and the head wires. I was pretty upset about it, but my dad helped me repair the gearbox using epoxy, it was agreed that it would be ok if the fan didn’t work, since it was “dangerous to fingers”. I cleaned up the metal as best I could, or rather as much as I was patient enough for. I painted the fan black and polished the brass. I looked good, it just didn’t work any more, and it served as a “knick-knack” for the next 23 years.

A couple of months ago, I pulled down the old knick-knack from its high cupboard perch in the kitchen to dust it off. While I was cleaning it, for some reason I decided now was time to fix it, and to refinish it correctly. I started by stripping the fan down completely, even removing the motor from it’s housing so I could fix the head wires on the motor. My impatience during my my first attempt to refinish the fan was evident by simply looking at the parts, the rust had not been completely removed and it left many areas with a rough finish through the paint. I had also attempted to reassemble the fan before the paint had fully cured which left many handling blemishes. This time, I stripped all of the paint off the parts by soaking the parts in lacquer thinner. There was still quite a bit of rust on the parts, more than I remember leaving there the first time. I did not want to lose any more metal, sanding was out of the question, so I soaked all of the parts in a rust removing solution, this removed all of the rust and left the remaining metal intact. The old epoxy I used on the gearbox was still holding strong, and I filled any visible cracks with new epoxy. I filled what pitting was on the metal with epoxy and refinished all the metal parts in Hunter Green enamel paint. The brass was polished and clear coated to prevent any further corrosion. New fabric covered electrical cord replaced the old, new grease was added to the gearbox, and new 3-in-1 motor oil was added to the oil cups. After 2 months of work, the fan looks great, and now it runs great as well, no longer a candidate for the dump……….

Front Left..
1927 GE AOU Fan Pic 3

Back Right..
1927 GE AOU Fan Pic 4

1927 GE AOU Fan Pic 5

1927 GE AOU Fan Pic 6

Front Right Running..
1927 GE AOU Fan Pic 1

Front Left Running..
1927 GE AOU Fan Pic 2

Video Running, Stationary..

Video Running, Oscillating..


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Infinity Ward loses a lifetime customer

I proudly own all of the Call of Duty games that have been produced. My children and I have enjoyed them, and we have spent untold hours playing against each other in our own private wars over our home network.

But sadly, no more!

I purchased Modern Warfare 2 with the expectation that I would get the same great value for my money that I had with all of the previous games. It turns out that many changes had been made to the game that for my family destroys the value, and fun, we had come to expect in the franchise.

The inclusion of Steam was the first offense, no longer could I play with my sons and daughter, battling against each other for bragging rights without spending 4 times what it cost before. Unable to justify the now $240 cost, our private “wars” have to end with World at War. Infinity Ward’s quest to extract a kings ransom from my family to enjoy this game has left a very bitter taste, one I will not swallow.

But even more egregious, and frankly infuriating, is Infinity Ward’s decision to drop the ability to have multiple single player profiles available in Modern Warfare 2. This flagrant ploy (there is no other word to describe it) to force us to purchase multiple copies of the game to play the single player campaign is unforgivable.

Infinity Ward has diluted this value of the game to a point that I will NEVER purchase another game from the company. The value of the previous games in the franchise lured me in, but I was conned. This game has little value to my family, my son has played it, the rest of us wanted to….. but I will not submit to the extortion Infinity Ward demands.

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Dr. Halbrook responds to critics.

Stephen Halbrook responds to some critics in a new article; NAZISM, THE SECOND AMENDMENT, AND THE NRA: A REPLY TO PROFESSOR HARCOURT

In a symposium published by the Fordham Law Review, Professor Harcourt and other have written very poorly sourced and argued paper criticizing the NRA and others. Their treatment of the topic borders on an attempt at revisionist history. Dr. Halbrook’s response is a powerful and compelling rebuttal to their claims.

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