2009 6.0L AFM delete

[Tunnelgas]

Good afternoon.  First post to thread.  Thanks in advance for any assistance and guidance.

 

A little background...my apologies in advance if I do not explain everything properly as I am not a mechanic...rather a tinkerer with what I would like to think is some common sense and understanding.

 

I have a 2009 Suburban 1500LTZ 4x4 with a 6.0L.  It has 160,000 miles give or take and has been an excellent vehicle for our family.  At around 150,000 miles it dropped a lifter.  At that time, I pulled it down and replaced just the one lifter, put it back together and it ran fine for about 10,000 miles until it recently lost another lifter.  

 

I spoke to an engine shop around town and they suggested that I should have gone ahead and replaced all of the lifters and the cam when I pulled it down the first time and that I should do that now.  They also suggested I do away with the AFM.  I did a little research and found that some had done this with good success.  I reached back out to the engine shop and they indicated that they sold a kit for this.  The kit included new replacement valley plates, new LS7 solid lifters, etc.  I confirmed with them that a stock cam could be installed and I ordered that directly from Chevy.  I also ordered a new oil pump.

 

I methodically went through everything, buttoned the engine back up and started the engine.  It had a knock in it but it had not been tuned yet so I didn’t think much of it. I trailered the vehicle to that engine shop to have the AFM tuned out of the ECM.   They commented there that they thought the knock was a piston issue.  I had a hard time believing this since it was running perfectly prior to loosing the lifter, but the knock is bad!  I have checked compression and it is good in all cylinders.  I made up a test plate to check oil pressure coming out of the oil pan and put another gauge in line at the sending unit.  I am getting a fairly steady oil pressure of 30lbs at the bottom (seems a little low) but it fluctuates between only 7-12lbs on the other gauge.  I pulled the engine back down and checked the lifters and cam...they seem fine.  I checked the bottom end when I pulled the oil pan and everything seems fine there as well.  

 

For the life of me I cannot determine the cause or source of the knock.  It does not get better when it is warmed up.  I have driven it a little just to see if anything else presents itself as a problem.  The engine is not missing at all, accelerates fine, etc.

 

Any ideas on where I should look or what I should do?  In hind sight, I guess I should have just replaced the lifters and cam with stock parts but from what I was reading the AFM delete was pretty straight forward and when the engine shop told me they sold a kit I thought it would be a good time to simplify things.  I am now wishing I hadn’t but remain hopeful that there is some experience that I lack that can help me get things back in line.

 

Thanks,

Steve

 

 

[Jsdirt]

With these engines, any kind of knock would have me looking at a long block replacement. The 6.0 is historically better than the 5.3 (if you had the 5.3 of that same year, you'd be lucky to see 130k miles) , but it's still a GM product - if they can save a buck on something, they'll do it, even for a 100 engine run on the line. You may have got one of them ...

 

This place is great for AFM delete info and options ... but at 160k, I'd be saving for a long block, unless you have the motivation to tear yours down, and find the source of the knock. I hate the way these LS's are built - a total pain in the ass compared to the simple 350. So many little, critical parts, and passages. Even as a tech I'd still go with a long block, because you could spent thousands ... not to mention all the trips back and forth to the machine shop, and all your labor, just to have the thing grenade because of a .50 cent o-ring that was forgotten, pinched, or failed.

 

https://www.texas-speed.com/csearch.aspx?CategoryID=0&ManufacturerID=0&SectionID=0&PriceRange=0&SortBy=1&PageSize=12&AndOr=AND&DisplayMode=Grid&Condition=-1&Search=afm delete

 

Remember, cam noises will sound at HALF the speed of the crank. If the sound is going at crank speed, it's more than likely a spun bearing, wasted wrist pin bore, or anything in the lower end.

[Tunnelgas]

Thank you for the response. 

 

I got with the guys in our shop yesterday and they suggested a long block replacement as well.  I am doing some research this morning to see what my options are. 

 

Whatever I do, I want it to be absent any of the AFM crap that I feel caused the issue in the first place.  This has been extremely frustrating as the first 150,000 miles I put on the Suburban were trouble free.  The interior and exterior look brand new...it has been extremely well taken care of and I would have hoped that as well as it has been maintained and babied I would have been able to get many more  miles out of the engine.

 

Any suggestions on where to go for the long block or other options/opinions would be appreciated.

 

Thanks you again for the response.

[diyer2]

I would go with a GM block from my local dealer.

More money but probably a better warranty and if any issues someone to talk to face to face.

 

[Jsdirt]

I have a different opinion on that. The way I see it, I will NOT reward the company that put me in this situation to begin with.

 

I'd find a reputable ENGINE BUILDER to buy a long block from - someone who does nothing but build engines day in and day out. The engine will be cheaper, better built, and will last longer & have a BETTER warranty to boot. They take the time to balance rotating assemblies, spend the money on QUALITY components, and know all the little tricks to get the most out of the engine as far as power, and longevity go.

 

Been a long time since I've bought an engine, but spending a few hours on the net researching different places will yield good results. Google is your friend here - when you do find a company, make sure to run their name and see if there's a laundry-list of complaints, or, if there's raving reviews.

 

Here's a place that sells alot of engines through many different sources, like Summit, Jegs, etc.. Can also buy direct:

 

https://blueprintengines.com/collections/gm-compatible-crate-engines

 

Doesn't have to be a performance engine - you can call and see if they will build just a stock LS. Don't see why they couldn't with their tooling.

[Justin101714]

The L96 6.0L doesn’t have afm. Do you have a L67? Maybe? They were used in the hybrid models.


Sent from my iPhone using Tapatalk

[Dnt]

?? you meant the L76 I think? The aluminum block with AFM and VVT 6.0 that was used in some LD trucks and SUVs 07 to 09? So many engine codes that it is impossible to keep up with LOL

08 and 09 Hybrids used the LFA aluminum block 6.0 with AFM and VVT. I currently have one in a 09 Tahoe Hybrid that has 198k on it and seems to be doing very well. looking for at least 300k out of it. Averages around 17MPG  

From what I have read the 2010 and up Hybrid 6.0 engine was designated LZ1 they basically just added the FlexFuel to the LFA and called it a LZ1?   

L96 is the iron block HD workhorse that does not use the AFM. I cannot count the number of 3/4 ton GM HD trucks that I have seen with over 350k miles still running strong, this engine is very impressive and absolutely tough as nails. Only problem I saw was the very poor MPG it seemed to hover around 10 MPG or a

lot LESS LOL but it would basically haul anything you loaded and pull anything you hooked to it flawlessly. Millions of these still out there chugging away everyday.