automatic fuel management disaster in GM vehicles

[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.

 

[ironman_gq]

The new ones are better, haven't heard of any issues from anyone I know that has one. The older ones definitely did have issues with oil consumption and cam/lifter issues. Best bet is to either quit buying the older ones or turn of the cylinder deactivation.

 

[TmanP]

Oil consumption is a fact of life for some engine designs. Half a quart every 600 miles is a quart in 1200 miles. Toyota says in their owners manuals that "acceptable oil consumption" is a quart in 600 miles, or twice what you're experiencing. I believe that GM's threshold is a quart in 1200 miles. I wouldn't call that a disaster by any means.

 

[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.

 

[Win]

Originally Posted By: pacem


.....

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.



Uh, okay.

None of my GM engines consume detectable amounts of oil over the course of the OCI dictated by the OLM.

That said, I didn't want an AFM engine. It's one ( not the only ) reason my G8 lacks the V8.

 

[dlundblad]

I'm not really a GM "fan" but I've never heard of any of the issues you're describing. Tahoes as well as that drivetrain are pretty tough.

Sounds like PO neglect to me. Why'd you buy it if you knew it had no oil in it?

 

[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?

 

[Jimzz]

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.



How is that GMs fault? All vehicles use oil and if you do long change intervals if the oil gets low enough it can start to do extra damage. Multiply that over and over and it will start to use even more oil as time goes on.

 

[pacem]

Originally Posted By: Win
Originally Posted By: pacem


.....

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.



Uh, okay.

None of my GM engines consume detectable amounts of oil over the course of the OCI dictated by the OLM.

That said, I didn't want an AFM engine. It's one ( not the only ) reason my G8 lacks the V8.


Of course they don't. they shouldn't. You just admitted you don't have AFM.

AFM is what causes oil consumption. Check out tahoeyukonforum.com there is plenty of data there.

 

[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.

 

[Nick1994]

You bought an auction vehicle. Big risk, someone dumped it there for a reason.

 

[Blueskies123]

A distant family member has a newer Cadillac Escalade that threw a piston while driving through some hill country in North Carolina. The Tech said these new engines are too smart for their own good. Go figure.

I would try to avoid all those complicated engines.

 

[pacem]

Originally Posted By: Jimzz
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.



How is that GMs fault? All vehicles use oil and if you do long change intervals if the oil gets low enough it can start to do extra damage. Multiply that over and over and it will start to use even more oil as time goes on.



How is it GM's fault - Do you have a reading comprehension problem? I just went over that. Do you not see there is a problem when you have to add oil to the motor nearly every time you fill up? That is not normal despite what the "official" Cover-Your-*** statement may be, of course they will deny it in their lawyer-speak. that it's normal. Repeating the party line is naive. It's not industry standard by any means. I've had toyotas that didn't use a drop of oil between changes. I've had a normal 6.0L engine in a Chevy without that AFM BullShyte that used about a quarter or less between changes and that was vastly better.

AFM causes huge oil consumption, turning it off changes that.

A neglectful PO, possibly one of these "woman-driven vehicles" you know, the ones that check oil once in the blue moon combined with flawed GM design is a problem.

 

[pacem]

Originally Posted By: Nick1994
You bought an auction vehicle. Big risk, someone dumped it there for a reason.



There was a reason and that was a repossession. Bank repo. Non-payment.

They did kind of neglect it a bit, had a fender bender that took me 700 to fix. Need to do motor mounts, some kind of emission thing needs to be replaced - I pulled the codes, the truck smells like fuel all the time and it makes some kind of noise while above 60-70mph, I am hoping it's just the tires and not the wheel bearings or something. Poor QC all around, but it's a better deal than Toyotas that sell for twice as much. Maybe.

You cannot buy a vehicle stickered for 40K for 6K and not expect to put some coin in it to the tune of 2-3 grand.

Even if I have a complete engine failure and replace it, I am still far, far ahead of buying new.

 

[Jimzz]

Originally Posted By: pacem
Originally Posted By: Jimzz
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.



How is that GMs fault? All vehicles use oil and if you do long change intervals if the oil gets low enough it can start to do extra damage. Multiply that over and over and it will start to use even more oil as time goes on.



How is it GM's fault - Do you have a reading comprehension problem? I just went over that. Do you not see there is a problem when you have to add oil to the motor nearly every time you fill up? That is not normal despite what the "official" Cover-Your-*** statement may be, of course they will deny it in their lawyer-speak. that it's normal. Repeating the party line is naive. It's not industry standard by any means. I've had toyotas that didn't use a drop of oil between changes. I've had a normal 6.0L engine in a Chevy without that AFM BullShyte that used about a quarter or less between changes and that was vastly better.

AFM causes huge oil consumption, turning it off changes that.

A neglectful PO, possibly one of these "woman-driven vehicles" you know, the ones that check oil once in the blue moon combined with flawed GM design is a problem.



No you did not. You bought a beat up used truck at auction and are trying to blame GM for lack of upkeep by previous owner. You even admitted when you bought it that the engine oil was very low. You expect the toilet paper company to wipe your [censored] since you buy their product? So why do you expect GM to do all the upkeep after people buy their vehicles? Its called taking some responsibility for ones self and putting the blame where it truly sits, bad upkeep and maintenance.

If this problem was as wide spread as you think it would have made news and many lawsuits.
Toyota had oil burning issues in many of its cars in the last decade. They were sued and they also extended the warranty for 10years/150k due to it.

 

[eljefino]

This is why I still buy GMs used even though they get annoying at times. They're a good value vs the competition, I can turn a wrench, and the 3rd party vendors came up with fixes for OE shortcomings.

Yeah it's not a free fix like the 1980s cadillacs where you cut the "3rd gear wire" from the tranny to disable the V8-6-4. But the motoring public made fun of the V8-6-4 situation for 35 years now... it's out there.

 

[pacem]

I am gonna have fun with the tuner. I think I will enable the 93 octane tune.

 

[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.

 

[ls1mike]

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.

The original LS1 had a designer who moved from Ford to GM. His name escapes me right now.
The current LT version was built on what was learned from the LSx.

 

[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.