automatic fuel management disaster in GM vehicles

[PhillyJoe]

Originally Posted By: 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.


I was referencing Pontiac Grand Prix's, but I looked at Tahoes from 2008 and they were 4 speed auto also.

 

[pacem]

2008 was the last year for 4L60 4speed. I was kind of hoping to get a 09 Tahoe but they were considerably more expensive than 07-8 Tahoes for some reason. As in between 10-14 grand.

 

[MNgopher]

Not stating that AFM is or isn't an issue. I have not been in the GM arena on these for a very long time.

However, I am chuckling at the idea that buying nine year old vehicle with 160,000+ miles at auction that was a bank repo with an unknown maintenance regimen in any way shape or form somehow leads to the conclusion the manufacturer is the problem. With it being such a big problem apparently, you should have known that before you bought. (Kind of like anyone looking at an '04 to '07 F150 with the 5.4 - the first two questions are: have the plugs been changed and have the phasers been done?) There is a reason why the price is where it usually is on things like this - and its up to the buyer to know and understand it.

Too expensive? Don't buy it then...

 

[ls1mike]

Originally Posted By: PhillyJoe
Originally Posted By: 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.


I was referencing Pontiac Grand Prix's, but I looked at Tahoes from 2008 nd they were 4 speed auto also.


Right 2009 was for the Tahoe. HD Trucks got it in 2007 along with the Escalade my mistake.

 

[ls1mike]

But I digress. AFM does cause oil to burn, and other problems. However that is not your only problem with the Vehicle. That is a lot even with AFM.

The Caprice needs no make up oil between changes. You sure the rings don't have build up?

 

[Tomioka]

I wonder if someone logged a lot of miles on the new EcoTec3 engines and had oil burning issues yet? It looked good on paper and was pretty impressed when I drove a 2016 GMC Sierra 5.3L.

 

[A_Harman]

Originally Posted By: 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.


The truck has 162k miles on it, is 9 years old, has been crashed, repossessed, and neglected by the previous owner.
So now it burns 1 quart of oil in 1200 miles.
How is this proof of poor QC at GM?
So use your $260 tuner and turn off the AFM. You got a good deal on a used truck, but you probably could have picked a better one.

 

[Ethan1]

Originally Posted By: 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.


Tahoe = Expedition, Suburban = Expedition EL

 

[demarpaint]

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.


I agree. The problem is the public always does the final testing for every new technology as they roll it out. CVT, DI, early EFI, you name it. The engineers don't always know best.

Sometimes they learn as they go, at the consumer's expense. Sometimes it takes years for them to learn. Then just when the get it right, the technology is obsolete and the cycle starts all over again with something else.

I stay clear of the first couple of years of any new technology. Even that is not always a guarantee there won't be problems.

 

[AZjeff]

Man am I stupid. The 2016 Silverado I just bought has the 4.3 with AFM AND GDI....what was I smoking?? Did my research, know what I got myself into and have a maintenance plan. If you want a newer GM truck you deal with it. Looked at all the full size trucks and GM was best fit.

There's no denying that the early years of DOD/AFM had problems, there's plenty of anecdotal evidence on any vehicle forum that uses these motors. And it doesn't seem to matter if the maintenance was neglected or obsessed over, some of them fail. A guy at work has an 08 5.3 Silverado he bought new now with 115K mostly short trips, he's a Walmart oil change guy and he's had no problems at all to date but it could fail tomorrow.

I wouldn't buy an 07/08 GM V8 knowing their problems, but a 160K 9 year old truck with signs of neglect could just as easily be an oil burner without the AFM. Turning if off isn't going to fix your oil use BTW. There are some guys on www.silveradosierra.com forum who claim to have reversed oil use but it involves more than just turning the AFM off.

 

[CKN]

Originally Posted By: demarpaint
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.


I agree. The problem is the public always does the final testing for every new technology as they roll it out. CVT, DI, early EFI, you name it. The engineers don't always know best.

Sometimes they learn as they go, at the consumer's expense. Sometimes it takes years for them to learn. Then just when the get it right, the technology is obsolete and the cycle starts all over again with something else.

I stay clear of the first couple of years of any new technology. Even that is not always a guarantee there won't be problems.



Most on here would like to go back to the 1960's. So your not alone.

 

[Trav]

Originally Posted By: AZjeff
a 160K 9 year old truck with signs of neglect could just as easily be an oil burner without the AFM.


+1 That's the truth, If it was a pristine low mileage one owner with a good maintenance history and burning oil like its 10c a qt then his conclusions might have more validity but his situation could apply to any neglected engine.

 

[HerrStig]

Originally Posted By: 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.
Yeah, sure, I've got FOUR Toyota vehicles and none burn oil. My 08 V6 level doesn't move a fraction of an inch in 5K.

 

[benjy]

GM is building some [censored] stuff for sure + its not getting better with new turbo'd engine issues!

 

[rotorcraft230]

I have a 2006 Silverado and it dosent have the cylinder deactivation 4.8L and I don't add any oil between oil changes because it dosen't use any,(maybe 1/2 quart at 5000 OCI) even after 240,000 miles. Maybe Igot lucky with my engine.

I do believe in the hard break in for new engines and I haven't ever had an engine that used oil.

 

[cb_13]

I see lots of 11-14 GM 5.3 trucks come in with the oil pressure light on. The screen for the sending unit gets covered in sludge. I'm not sure if it's lack of maintenance or a design issue but it's very common. One was entirely sludged up and metal shavings from where it ate up the cam bearings..

 

[umungus1122]

If the thing was 2.5 qts. low, I wouldn't buy it. If you don't know the maintenance history of a vehicle, don't buy it unless it's a ridiculous deal.

 

[Jimzz]

Originally Posted By: HerrStig

Yeah, sure, I've got FOUR Toyota vehicles and none burn oil. My 08 V6 level doesn't move a fraction of an inch in 5K.



Here is the notice direct from Toyota...

http://media.fixed-ops.com/Toy_WarrantyBulletins/pol14-12.pdf

This is a well known issue and they tried to sweep it under the rug but it kept getting worse and worse till they had to do this.

SUBJECT:WARRANTY ENHANCEMENT PROGRAM (ZE7) PHASE 1:
WARRANTY EXTENSION FOR EXCESSIVE ENGINE OIL
CONSUMPTION FOR THE FOLLOWING VEHICLES:
CERTAIN 2007-2009 MY CAMRY
CERTAIN 2007-2011 MYCAMRY HYBRID
CERTAIN 2007-2008 MY CAMRY SOLARA
CERTAIN 2009-2011MY COROLLA
CERTAIN 2009-2013 MY COROLLA MATRIX
CERTAIN 2006-2008 MY RAV4
CERTAIN 2007-2010MY SCION TC
CERTAIN 2008-2015MY SCION XB

ten (10) years from the date of first use or 150,000 miles, whichever occurs
first.

 

[AZjeff]

Originally Posted By: cb_13
I see lots of 11-14 GM 5.3 trucks come in with the oil pressure light on. The screen for the sending unit gets covered in sludge. I'm not sure if it's lack of maintenance or a design issue but it's very common. One was entirely sludged up and metal shavings from where it ate up the cam bearings..


2014 was the year of the redesign, changes to the AFM gear and now GDI. Can you differentiate between '13 back and '14 up?

 

[cb_13]

Originally Posted By: AZjeff
Originally Posted By: cb_13
I see lots of 11-14 GM 5.3 trucks come in with the oil pressure light on. The screen for the sending unit gets covered in sludge. I'm not sure if it's lack of maintenance or a design issue but it's very common. One was entirely sludged up and metal shavings from where it ate up the cam bearings..


2014 was the year of the redesign, changes to the AFM gear and now GDI. Can you differentiate between '13 back and '14 up?


No, I was strictly going by body style.