automatic fuel management disaster in GM vehicles

[exranger06]

Originally Posted By: CKN

No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.

It's 9 years old and has 162k miles on it. I'm pretty sure the warranty already expired.

 

[PhillyJoe]

I know several online Pontiac friends who had a GXP with the 5.3. First thing they did, even brand new, was diable the displacement on demand AFM. Never read about anyone loving it. First time I heard about it was with Cadillac - you could limp home up to 50 miles if you lost all of your coolant as only a couple of cylinders were firing.
Keep in mind, this is the same company that switched to plastic intake manifold gaskets in all of their v6 engines from 1997 to 2003. They degraded rapidly when they came in contact with dexcool and of course the coolant took the blame.
So here they are selling a 300hp 5.3l engine with a 4spd trans. I would have spent the R&D on a 6 or 8 speed transmission to save fuel, not AFM.

 

[ls1mike]

Originally Posted By: exranger06
Originally Posted By: CKN

No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.

It's 9 years old and has 162k miles on it. I'm pretty sure the warranty already expired.


Correct, but he originally said 400 dollars, that is not the case. I have a Diablo...no good. Should have applied the 260 to HP Tuners, which I do have for the WS6.

If you just want to disable AFM and not mess with a programmer or changing the ECM the Range Technology piece is perfect. Plug and go, remove when you need it to be stock.

 

[CKN]

Originally Posted By: exranger06
Originally Posted By: CKN

No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.

It's 9 years old and has 162k miles on it. I'm pretty sure the warranty already expired.



I'm aware of that-but mentioned the other points for anybody with a new vehicle with AFM looking at options.

 

[ls1mike]

Originally Posted By: PhillyJoe
So here they are selling a 300hp 5.3l engine with a 4spd trans. I would have spent the R&D on a 6 or 8 speed transmission to save fuel, not AFM.


He does have a six speed.

 

[VNTS]

Originally Posted By: pacem
So I got a 2008 Tahoe with the AFM feature..

what an idiotic failure by GM. They had to take a good engine and screw it up big time without admitting it. They add features the public doesn't want or need, make things complicated and their QC is so poor that they fail.

My 5.3L sucks oil by the gallon. Half a quart of oil every two fill-ups. Or 600 miles. Ridiculous doesn't begin to describe it.

When I bought the car (used), it didn't register any oil at all on the dipstick. Had to add 2.5 quarts. Because you have to add oil on a weekly basis and evidently the PO wasn't checking it often enough.

I mean they are a multi-billion "dollar" corporation, they should act better than some garage start-up on a shoe-string budget and really test their stuff before releasing it to the public. They dropped the ball on it. There is a reason why used auto market heavily discounts GM versus say other brands. Because you may need to put several thousand into it when you get it. Case in point, engine mounts, another glorious design failure.

I am going to turn off the stupid 4-cyl mode and just hope it hasn't caused issues already. With lifters. 162K miles and 5000 hours on 5.3L.

I paid 6K for the vehicle, had to put another 2K in it to make it drivable. 8K is not bad but there is no way I would pay 50K for such an abysmal lack of QC/design stupidity. I doubt the new ones are any better.


If it was 2.5 qts low, and you knew it, why did you buy it?? sounds like previous owner must of neglected it.

 

[pacem]

Originally Posted By: CKN
Originally Posted By: pacem
Originally Posted By: ls1mike
Originally Posted By: pacem
No, it is not a fact of life. oil consumption stops when the AFM is turned off. That is the point. It's the side effect of AFM. They should have at least provided an easy way to disable it versus buying a $400 tuner and DIY or taking it somewhere for a tune. Dumb as a doorknob.

This is why a 2008 Tahoe runs 6-8K and same year Toyota SUV runs 15K.



Slow down...You have something else going on too. I have AFM in the Caprice...Your research is flawed. 400 dollar tuner? Range Technology 189.00 dollars shipped. Plug it into your OBD II port. No more AFM/DOD

Range Technology

How man miles on the truck? What was it used for?


The range device is a pretty poor deal considering that's the only thing it can do.
I ended up with a Diablo i2030 tuner for 260 that can retune a lot of other things, like octane changed to 89 and such, tire size, etc. A vastly better deal than a single purpose Range.

The mileage/hours are in the original post.



No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.


Self-evidently, there is no warranty on a 2008 vehicle.. None. So, it's a moot point. Isn't that obvious?

 

[pacem]

Originally Posted By: VNTS
Originally Posted By: pacem
So I got a 2008 Tahoe with the AFM feature..

what an idiotic failure by GM. They had to take a good engine and screw it up big time without admitting it. They add features the public doesn't want or need, make things complicated and their QC is so poor that they fail.

My 5.3L sucks oil by the gallon. Half a quart of oil every two fill-ups. Or 600 miles. Ridiculous doesn't begin to describe it.

When I bought the car (used), it didn't register any oil at all on the dipstick. Had to add 2.5 quarts. Because you have to add oil on a weekly basis and evidently the PO wasn't checking it often enough.

I mean they are a multi-billion "dollar" corporation, they should act better than some garage start-up on a shoe-string budget and really test their stuff before releasing it to the public. They dropped the ball on it. There is a reason why used auto market heavily discounts GM versus say other brands. Because you may need to put several thousand into it when you get it. Case in point, engine mounts, another glorious design failure.

I am going to turn off the stupid 4-cyl mode and just hope it hasn't caused issues already. With lifters. 162K miles and 5000 hours on 5.3L.

I paid 6K for the vehicle, had to put another 2K in it to make it drivable. 8K is not bad but there is no way I would pay 50K for such an abysmal lack of QC/design stupidity. I doubt the new ones are any better.


If it was 2.5 qts low, and you knew it, why did you buy it?? sounds like previous owner must of neglected it.


I got the car, checked all the fluids - well most fluids and topped off the ones that needed it. The oil took about 2 quarts for sure. It's a sign that the engine drinks oil. It does not have any residual effect.

 

[pacem]

Originally Posted By: ls1mike
Originally Posted By: exranger06
Originally Posted By: CKN

No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.

It's 9 years old and has 162k miles on it. I'm pretty sure the warranty already expired.


Correct, but he originally said 400 dollars, that is not the case. I have a Diablo...no good. Should have applied the 260 to HP Tuners, which I do have for the WS6.

If you just want to disable AFM and not mess with a programmer or changing the ECM the Range Technology piece is perfect. Plug and go, remove when you need it to be stock.


Missing the forest for the trees. What difference does it make? The diablo tuner retails for 400 or something, I scored one for less. Says who it's no good? I checked amazon reviews on all the major tuners and that particular one had decent reviews.

I don't want to "just" disable the AFM as I made it perfectly clear but tune a number of parameters. that is where its value is realized. the range device you can get on Ebay all day for under 100 bucks because that's all it's worth.

 

[pacem]

Originally Posted By: PhillyJoe
I know several online Pontiac friends who had a GXP with the 5.3. First thing they did, even brand new, was diable the displacement on demand AFM. Never read about anyone loving it. First time I heard about it was with Cadillac - you could limp home up to 50 miles if you lost all of your coolant as only a couple of cylinders were firing.
Keep in mind, this is the same company that switched to plastic intake manifold gaskets in all of their v6 engines from 1997 to 2003. They degraded rapidly when they came in contact with dexcool and of course the coolant took the blame.
So here they are selling a 300hp 5.3l engine with a 4spd trans. I would have spent the R&D on a 6 or 8 speed transmission to save fuel, not AFM.



yeah, all true.

Hard to believe GM hasn't learned from that 1980's Fiasco with 4-6-8. Why or why did GM not include a simple DIY deactivation in the menus.

It sounds like one department came up with the engine which is good, then another one, not related to the former, decided to improve it and put the dreaded AFM on it. It doesn't even save any gas savings (MPG) at all when it's working. Seems like several departments are not communicating. Just my guess.

1980's called and they want the AFM back.

 

[ls1mike]

Originally Posted By: pacem
Originally Posted By: ls1mike
Originally Posted By: exranger06
Originally Posted By: CKN

No-it's actually a good deal-it turns off the AFM and doesn't overwrite the vehicles software-like your Diablo does allowing GM to void your warranty. And yes-GM can tell an "event" took place on the ECM even if you change it to a stock tune prior to taking it back to a dealer for warranty work.

It's 9 years old and has 162k miles on it. I'm pretty sure the warranty already expired.


Correct, but he originally said 400 dollars, that is not the case. I have a Diablo...no good. Should have applied the 260 to HP Tuners, which I do have for the WS6.

If you just want to disable AFM and not mess with a programmer or changing the ECM the Range Technology piece is perfect. Plug and go, remove when you need it to be stock.


The diablo tuner retails for 400 or something, I scored one for less. Says who it's no good? I checked amazon reviews on all the major tuners and that particular one had decent reviews.


Someone who has an 11 sec 1/4 mile heads and cam Trans Am. The Diablo is worthless for that.

 

[Ethan1]

LOL @ people denying that AFM causes oil consumption. Disabling AFM was step one for everybody I know with a 5.3, which includes a lot of dealer techs.

 

[pacem]

Originally Posted By: ARCOgraphite
My 4.3 ( based on classic 5.7 architecture) sucked oil new. About a qt every 1500. I Imagine It was a combination of the open PCV (un-baffled design) and hard driving. These new V8 engines ain't classic SBC. Designed by an Indian guy I hear.

160K miles on a 9 year old car with body damage for is LONG long cash. Wholesale has got to be 2200-2700. Sticker price don't matter at end of service life on a non-"classic" commodity car.


Right, you just show me where I can get a 2008 Tahoe for $2200-2700. I will tell all these people sticker price doesn't matter where they ask for 9000 and such on Tahoes and Suburbans of that vintage.

Tahoes go for 6000-8000 at dealer only auctions FYI, circa 2008-09. Same year Toyotas, like Tundra/Tacoma and 4runner, depending on options, go for as high as 15000. That's with the same mileage, 150 and up. It holds it value to the point of absurd.

I suppose I could get a 4runner or a Tundra for 14-15K but not so sure it wouldn't have any issues either. the rusted frame scandal stopped me, so GM is not all bad versus Toyota all good.

 

[pacem]

Quote:

Someone who has an 11 sec 1/4 mile heads and cam Trans Am. The Diablo is worthless for that.



This thread is not about a racing Trans Am, is it now?

When I had a racing car, I got a custom tune from PCMforless and was happy with it.

 

[ls1mike]

Originally Posted By: pacem



Someone who has an 11 sec 1/4 mile heads and cam Trans Am. The Diablo is worthless for that. [/quote]


This thread is not about a racing Trans Am, is it now?

When I had a racing car, I got a custom tune from PCMforless and was happy with it. [/quote]

Nope but you started talking tuners, I can talk about those all day. When you really want to do it correctly you get HP Tuners take it the dyno and move on.

 

[pacem]

Fabulous. I got the Diablo because the guy behind is on a GM forum is in touch with the users and emails them the recepis. The high priced tuners all seem to do the same thing but this one item striked me as favorable.

 

[oilpsi2high]

Yeah, I definitely wouldn't buy anything with AFM. Huge marketing gimmick and a complete failure in the real world.

Even 2017 models with a new engine, you won't be able to tell if those issues were fixed until it is several years old. I was looking at the Colorado with the 3.6 and lost interest when I found out that they added AFM to the 2017's. No thank u!

 

[ls1mike]

So what was your "racing" car. What was done to it. A canned tuner for a heads and cam car is not going to work just right.

 

[oilpsi2high]

Quote:


Nope but you started talking tuners, I can talk about those all day. When you really want to do it correctly you get HP Tuners take it the dyno and move on.


This. Unless you have a wideband and HP Tuners Pro (or standard if you're cheap and know how to hack the PIDs), and know what you're doing, then don't bother with a canned tune.

 

[pacem]

I think my next ride will be a Ford to be perfectly honest... Not sure what the Tahoe direct competition is, Explorer maybe? Does Suburban=Expedition. I liked the feature set on GM cars a bit more, for example Suburban has a slightly bigger gas tank than Expedition.