Just bought a 2012 Z-something Tahoe and may have lied to by dealer? An engine idle thimg.
- Thread starter MarvinVR
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Let's see a picture of the RPO codes from the glovebox lid.
EddieC
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I just ran across something that might be of interest regarding AMF disablers:
Read all the way through.
BEWARE Range AFM disabler or turning off with HPT - CorvetteForum - Chevrolet Corvette Forum Discussion
C7 General Discussion - BEWARE Range AFM disabler or turning off with HPT - I have had either a Range AFM disabler or AFM disabler for about 35000 miles. A GM tech I know had told me at one point that it's common that when that system is disabled for a long time, and then subsequently re-enabled...
www.corvetteforum.com
Read all the way through.
EddieC
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Maybe.
I see that all the time on my Labrador Retriever in the woods.
When her nose is working her ears shut down.
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MarvinVR
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most Ive learned about fixing stuff was because I broke it to begin with by playing with it to make it 'better' The more I think about this problem---I believe its my heart murmur!!! Getting old sucks. I can hold a screwdriver but need a second person to put the blade in the slot.
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MarvinVR
Member
That was interesting reading. So once again I dont know which way is up. AFM kills---turning off AFM kills. Last year a glass of wine made ya ive longer---this year it will kill you. Good Jesus. And my new scanner with AFM disabler is on the way. How do we get a bottom line truth for this?
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MarvinVR
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OK Gang--just ran this through three different AI sites, Gemini, ChatGPT and Claude. Im attaching a 15 page document that, unlwess you have something to add or change, should answer anyones questions about AFM. Its left me confused about what to do, and wishing I hadnt bought a 5.3
Hey you
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I have the AFM plugged in to the OBD port, works great. Now looking for a brain disabler as mentioned by EddieC!
Don't overthink it. Just use a disabler or tune it out.
A couple of times a year after an oil change ill remove the disabler for about 5 miles just to keep the system cleaned out and working in case it ever gets sold for a newer truck.
Wifes 2013, 5.3 Avalanche.
A couple of times a year after an oil change ill remove the disabler for about 5 miles just to keep the system cleaned out and working in case it ever gets sold for a newer truck.
Wifes 2013, 5.3 Avalanche.
mikez71
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A tune is THE way to go.
The only drawback is time, because you have to mail it in and wait a couple days. (Unless you know someone local)
The only drawback is time, because you have to mail it in and wait a couple days. (Unless you know someone local)
EddieC
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A third to twirl you around?
EddieC
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I'm just driving mine stock until it croaks and then move on.
Like my urological oncologist once explained, something else will probably get ya sooner.
If AFM is allowed to function, you will experience a lifter failure at some point where one or more of the AFM lifters doesn't return to normal when the ECM tries to exit AFM mode
Disabling AFM does usually extend the amount of time before a lifter failure occurs but the lifter design on the AFM cylinders is still prone to issues, many people do well using a disabler scheme & being very diligent with oil changes; this is the cheapest option if you haven't had a lifter issue yet
Of the disable options the safest is to have the system turned off in the ECM, the OBD port disablers will stop working if they wiggle loose or the fuse blows that powers the port, if a fuse blows the only immediate symptom is one of the accessory ports stops working so the AFM can resume operation before you notice the issue. This is dangerous because the longer those lifters have been disabled the more likely they will fail when reactivated
I would advise having someone tune the ECM to permanently disable the AFM system & disable all codes related to the AFM system so nothing is relying on the OBD port in perpetuity, then use a catch can and change the engine oil frequently; short of physically replacing the internal AFM components this is the best approach I know of
Good luck!
Disabling AFM does usually extend the amount of time before a lifter failure occurs but the lifter design on the AFM cylinders is still prone to issues, many people do well using a disabler scheme & being very diligent with oil changes; this is the cheapest option if you haven't had a lifter issue yet
Of the disable options the safest is to have the system turned off in the ECM, the OBD port disablers will stop working if they wiggle loose or the fuse blows that powers the port, if a fuse blows the only immediate symptom is one of the accessory ports stops working so the AFM can resume operation before you notice the issue. This is dangerous because the longer those lifters have been disabled the more likely they will fail when reactivated
I would advise having someone tune the ECM to permanently disable the AFM system & disable all codes related to the AFM system so nothing is relying on the OBD port in perpetuity, then use a catch can and change the engine oil frequently; short of physically replacing the internal AFM components this is the best approach I know of
Good luck!
I haven't down loaded your file, but under general sub forum for this year you'll find this sticky up top. it was probably worth the read before making the dive. but what can ya do lol. I did a bunch of research and still bought mine and it's even more complicated. I got the hybrid version cause I found it interesting haha. all the afm issues with extra hybrid side stuff to fail. upside is I don't have a tq converter to fail and take the tranny out. bad thing is no one rebuilds hybrid trannys ha
Thinking of Buying a 07-14 NNBS Tahoe/Suburban? Look Here
Gentleman I have been put in charge of making a sticky with common questions asked on the forum. These include common problems (please provide fixes and pics), some of the common mods (provide pics, step by step instructions, etc.) i.e. not air ride but maybe leveling the rear or front. I am...
www.tahoeyukonforum.com
anyways. welcome and good thing is you're pretty low mileage at this point. you got a while before you need to slowly rebuild everything.
just keep the oil changed often like every 3k old school
all this 10k, 8k, 5k oil change crap is b.s.
just like it says in the manual 100k transmission fluid life, like hell!
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MarvinVR
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My urologist suggested that my 'delete' code had workled too well
This sounds like my '99 Yukon SLE, 5.7. Bought it with about 20k. Slight lope, only at idle of course, but figured that's what they do. Over time, it's slowly losing coolant. Checked plugs--# 7 slightly dark. Slowly tightened lower manifold bolts in that corner. Finally at about 120k miles the manifold to head gasket splits and I made it home about 4 miles with coolant and oil exchanging thoroughly. Careless trip, but, I got away with it!
Hand dressed the left rear blending to almost middle of the lower manifold face judging with light behind a straight edge. At not yet dead flat, but maybe good enough I put it all back together. Ran rougher than hell after assembly so limped over to the Autozone guys for help. Timing all over the place because coolant blocking looked like detonation. With one maneuver he reset all timing to default new and it smoothed right out.
The next 100k miles have been great. Other findings, it loves DEXOS oil, not Mobil Super. Gumout, Berrymans and dry gas.
Been a crummy car until lots of cheap flimsy parts replaced or modified. I once had a MAZDA that was worse, tho'. Now, the Yukon idles so smooth that it sometimes feels like it quit during any waiting.
Hand dressed the left rear blending to almost middle of the lower manifold face judging with light behind a straight edge. At not yet dead flat, but maybe good enough I put it all back together. Ran rougher than hell after assembly so limped over to the Autozone guys for help. Timing all over the place because coolant blocking looked like detonation. With one maneuver he reset all timing to default new and it smoothed right out.
The next 100k miles have been great. Other findings, it loves DEXOS oil, not Mobil Super. Gumout, Berrymans and dry gas.
Been a crummy car until lots of cheap flimsy parts replaced or modified. I once had a MAZDA that was worse, tho'. Now, the Yukon idles so smooth that it sometimes feels like it quit during any waiting.
sounds like an obs 99? the sbc 350 had water running thru the intake and a distributor that needed timing adjusted with a scanner.
great motor, little gm flaws here and there like coolent that ate the intake gaskets and the fuel injector spider under the intake but over all made less hp than a ls, but man they lasted as long as you felt like owning them.
mikez71
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I would go with HPTuners. You seem to know what you're doing, and you would have a lot more flexibility with HPTuners.
That said, you would still need a computer and it would take more time to tune.
But you would quickly change the easy stuff like AFM disable and also have a datalogger/scantool available.
If you like the extra display that the Edge tuner gives you, HPTuners scanner has a configurable display, buy it is crude looking and requires you to boot windows.
For extra display information in the dashboard, and a built in DTC reader among other BCM tuning features, I recommend the BTDieselworks AutoSync.
I have a 99 Express with a 5.7 and it ran ok when i bought it, When cold out it was impossible to start even with starting fluid.
New intake gaskets and converted to mpfi. It's the best running 5.7 i have ever had. Glass smooth and immediate start up at 230K.
HP Tuners is a great DIY program. Turning off vat's and disabling AFM is very easy. Anything more than that and it is an undercut cliff to learn.
New intake gaskets and converted to mpfi. It's the best running 5.7 i have ever had. Glass smooth and immediate start up at 230K.
HP Tuners is a great DIY program. Turning off vat's and disabling AFM is very easy. Anything more than that and it is an undercut cliff to learn.
