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Posted

Actually my 5.3 does say 0W-20....why doesyours say 5W-30?

Correct....it doesn't ...sometimes I forget the old Avalanches 5.3s took 5W-30, the new Silverado 0W-20. Over fifteen 5 qt containers of Mobil 1 left for the Malibu and Traverse & Camaro, lucky I still have five 5qt of 0-20W remaining from the '13 Malibu which I can now stuff into that pig Silverado which sucks up 8 qt.. That's why the filler caps are important....what's on the cap goes in the crankcase.

Posted

Thankfully the 6.0 gas engine is still IDI and has no afm. Plus the HD trucks have some things I prefer over the 1500's.

 

A few less mpg will not bother me.

 

 

So aside from regular oil changes, which I do at a set mileage by ignoring the OLM, what else do you do on these DI afm engines?

Might be a bit more difference than you think on the gas mileage thing. My 2016 Denali 6.2 8spd got this from Nashville TN to Chicago IL yesterday

I have never seen a 6.0 much over 12mpg LOL

 

Posted

Never understood it either. Why buy a V6 with gimmicks to get V8 power when you can just buy a V8 and bypass all the potential maintenance problems of turbo and intercoolers. Plus the ecoboost 2.7 and 3.5 don't outdo mpg wise the 5.3 and 6.2 in real world driving in many of the longterm tests out there.

 

 

Dang! And people by ecoboosts? Wish I had me a6.2L

  • Like 1
Posted (edited)

Never understood it either. Why buy a V6 with gimmicks to get V8 power when you can just buy a V8 and bypass all the potential maintenance problems of turbo and intercoolers. Plus the ecoboost 2.7 and 3.5 don't outdo mpg wise the 5.3 and 6.2 in real world driving in many of the longterm tests out there.

 

 

Yup, I feel those engines are just minutes away from major problems everyday.......I would bet not one of the drivers rips that engine all the way home, to work and just turns it off without idling down....disaster waiting to happen! No wonder the old timers would get bent if you drove their rig hard all the way back to the shop and didn't idle down properly? you will at some point have a turbo problem not a if but when.......

Edited by mookdoc6
  • 9 months later...
Posted

Does anyone know if the AFM problems were solved? Should I be concerned with the AFM in my new 2016 5.3L Silverado? thanks!

No they have not. Saw a 100k+ 2015 GM yesterday with complete failure, sounds like shit, exact same as my 2008 Suburban failure.

Posted

No they have not. Saw a 100k+ 2015 GM yesterday with complete failure, sounds like shit, exact same as my 2008 Suburban failure.

So that means it's an AFM problem? '07 and '08 were the worst years for an unmodified AFM engine and no surprise they failed..........dumped my '07 as soon as the warranty expired. But, more than likely poor maintenance following that engine killer OLM and ring wear, worn out of valve guides or buggered PCV system was the culprit in a later engine. AFM engines mfrd. after 1/2011 have all three AFM problem related causes corrected, i.e. AFM discharge shield, Valve cover with relocated PCV takeoff and modified valve lifters in the AFM cylinders. So same result, different cause.

 

And the GM first step cure for oil burning AFM smokers was to introduce a strong solvent into the intake manifold and let it sit for a few hours in an attempt to free up the oil rings in the affected pistons then an immediate oil change before running the engine........not to introduce the solvent into the crankcase. Later modes included valve covers, AFM shield, new pistons, and/or lifters- No idea what is in Seafoam, hopefully it has a high lubricity factor and won't cause damage, but doubtful it will free up any AFM frozen oil rings otherwise Chevy would have tried it as the first easy way out.......and it certainly won't do anything to fix worn valve guides or rings. Eight quarts in the crankcase so it would take a good amount of solvent to do damage, but too much solvent will wash the cylinder walls, increase friction and slow the pistons and at high rpm likely crack a piston ring.

  • Like 1
Posted

I am a bit worried about AFM issues as well, I only have 300 miles on the truck, but AFM never sounded like a good idea. Added complexity and failure points, I seem to remember the AFM Dodges having issues with those motors as well. Especially timing chain failures. I always wondered if balance was affected when 4 cylinders were deactivated and how it would affect engine wear and longevity. I'll be deleting AFM and tuning the trans as soon as I am out of warranty for sure.

 

If you want to try something to keep the rings from sticking and clean up junk in the motor caused by AFM, I'd try Archoil AR9100 before I used Seafoam. AR9100 worked extremely well for freeing stuck injectors in HEUI Ford motors, it's the only oil additive I have ever used that actually produced a noticeable difference. I've used it in my gas motors since then to clean up the internals and rings on old used vehicles I buy and add a little protection for the bearings. I usually just order it on Amazon.

Posted

I don't think they all are bad. My friend I work with has an 2007 silverado with a 5.3 and AFM. He has 137,000 on it and done nothing but oil changes since he has had it. I think there is a lot less problems than more.

Posted (edited)

All '07 5.3l AFM engines had the same basic design defects, but not all are necessarily doomed to be oil burners. Followed this in detail when I had my '07 Avalanche.

 

Two basic oil consumption problems: Poor location of the PCV takeoff on the valve cover where it was susceptible to oil spray directly off the rocker arms of the valve train; and AFM discharge valve located in the sump, the latter being the worst offender. During 4 cyl operation the oil diverted from the deactivated AFM lifters is discharged through the AFM valve which has one jet spraying vertically into the sump and four horizontal jets spraying onto the sump walls and lower ends of the cylinder walls.

 

Seems the oil sprayed from the horizontal jets onto the 4 deactivated "dead" AFM cylinders which lack the normal combustion temperatures/pressures as the 4 remaining "live" cylinders and the excessive oil overloads the lower oil ring sets on the pistons of the "dead" AFM cylinders, especially the rear cylinder closest to the valve. Eventually with time (usually noticeable around 40K miles) the oil ring set clogs with oil deposits and freezes. Once frozen the oil ring set can no longer flex and act like a squeegee to remove oil from the cylinder walls, the effect worsening with time and mileage..

 

Mods to remedy the problem on future engines included a new valve cover with relocated and baffled PCV takeoff port and a shroud over the AFM valve to redirect the spray from the four horizontal jets directly downward along with the fifth vertical jet into the sump to prevent oil discharge directly onto cylinder walls. All engines manufactured after 1/2011 have these changes along with modified valve lifters to prevent a sticking valve problem. Attempts to rectify the problem (under warranty) include solvent flush of the cylinders to try to free up the clogged oil ring sets, failing that piston replacement along with the valve cover/AFM shroud mods. No mods and the engine is predisposed to becoming an oil burner - and solvent flush was a short term fix if the frozen rings were significantly worn before solvent flush.

 

Never specified by GM, but my .02 on this is: The reason your friend and others may not have this problem is because they may have overdone it with oil changes and not followed that engine killing DIC. The primary AFM problem in an unmodified engine is clogged oil ring sets and the dirtier the oil (and increase of suspended ultrafines and decrease of detergent additives with mileage even though the oil retains its specified lubricity) the more burned combustion particles on the cylinder wall and the faster the oil ring set will clog and freeze. Changed my oil first 1K and every 3K after that, and at 40K when I dumped the '07 it never burned a measureable amount between the 3K changes. Reason for a lot of unmodified AFM's on used vehicles burn oil may be because the previous owner didn't maintain it early in the engine's life cycle and once the oil ring set is worn, even if freed up through a solvent flush, it's a goner.

 

The Range device which prevents 4 cyl operation will solve the basic cause of the problem, but cannot reverse the damage once it is burning oil.......all it" can do is prevent the damage from becoming worse.

 

Bottom line is I'm not worried one bit about my '16 AFM 5.3l

Edited by Thomcat
  • Like 1
Posted

That's reassuring to hear, I really like DI and the 5.3 itself. AFM and the odd 6l80e shifting strategy are the only things that bother me. Being that I am a tinkerer and fix all my own stuff, as well as tune it, it sounds like it will never be a problem. At least not one that I lack the capability to prevent. Once the engine is broke in on mine I plan to start running Archoil because I love how clean it keeps my engines, and have good experience with it fixing stiction and stuck rings. I also only use top tier filters and oil, which get changed around 6-8k miles or so, which is generally around once a year. We have lots of cars and split mileage between them all, but still change oil once a year even if I don't hit the mileage or wear it out.

Posted

I changed my oil at 8k. I've only changes it once but in that 8k I was low maybe 1/4 quart. I do have a catch can but I need to install it

Posted (edited)

As Thomcat stated, changing the oil at a faster frequency than the DIC wants you to will keep the older 5.3's happy and oil burning free. I also had a '07 Avalanche, which I traded this year on my current ride. I changed the oil in the old rig around every 5000 miles and never had any excessive oil loose between changes. That truck really served me well, ten years and just over 100k on it at time of trade. Just my opinion, keep the engine oil clean and the motor will be happy for as long as you have it.

Edited by needlepimp
  • 2 months later...
Posted

Might be a bit more difference than you think on the gas mileage thing. My 2016 Denali 6.2 8spd got this from Nashville TN to Chicago IL yesterday

I have never seen a 6.0 much over 12mpg LOL

attachicon.gifTrip A Nashville to Chicago10-5-16.JPG

Dang! And people by ecoboosts? Wish I had me a6.2L

Thankfully I have no plans on finding out about the afm system, I will be buying an ecoboost. No afm or oil guzzling to worry about, and dual injection takes care of carbon build up on intake vales that DI are known for.

Posted (edited)

Thankfully I have no plans on finding out about the afm system, I will be buying an ecoboost. No afm or oil guzzling to worry about, and dual injection takes care of carbon build up on intake vales that DI are known for.

 

Really, It will be in Direct Injection almost the entire time...Start up, working it slightly etc. other than modest Highway cruising your never going be in Port? You will not escape the Carbon the issues. Now you have twice the plumbing with oil and cooling etc! Turbo replacements which you will.....Classic FERD Electrical/Dash problems.....oh, you will see

 

Not to mention their not so seamless Start/Stop. GM has that nailed down among many other things AFM is the least of your worries...or GM's

Edited by mookdoc6

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