Last post on Nov 26, 2013 at 5:54 PM
You are in the Chevrolet Silverado & GMC Sierra
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GMC Sierra 1500, Chevrolet Silverado 1500, Fuel System, Truck
#342 of 415 Re: 2008 "Certified" used GMC Sierra [wvhotshot]
Mar 11, 2013 (8:40 am)
Update: After I got the truck back it has no low end power, a miss that it didn't have before and at hwy speeds the RPM is 400 higher than before. The engine also feels like it has a surge when driving down the hwy almost like it stops firing for a split second. The gas mileage has also dropped by 4mpg. I took it back and they had it for a week and then changed out the torque converter saying it was locking up too soon???? When I picked it up on Saturday and drove it and nothing was fixed from before but now when driving in slow traffic it feels like the thing has a stall speed converter in it. From a rolling start the engine revs up before the converter engages and you here it when it does go into engagement thru the drivetrain. They reprogramed the computer after doing the lifter work. Did GM make changes to the programing for the transmission shifting points and converter lockup? It is now the 4th week they have had the truck and all I keep hearing is ďwe donít know whatís wrong with it?Ē Please help
#343 of 415 Re: 2008 "Certified" used GMC Sierra [chuck1]
Mar 11, 2013 (8:43 am)
I need the pulling power. That is why I got the MAX tow package truck with the 6.0L.
#344 of 415 More GM AFM Pain!
Mar 12, 2013 (8:20 pm)
So I would like to discuss our recent troubles with our 2007 Chevy Tahoe LT 5.3L. We were finally able to purchase our first new car, 2007 Chevy Tahoe LT, ever in October 2006 from our local dealership. We decided on the Chevy Tahoe because we have had a used Chevy Suburban and Used Chevy Tahoe prior and have had excellent experience with both of them. It was truly a wonderful experience until now.
Flash forward to October 2012. While traveling several warning lights came on ďService Traction Control, Stablitrak, and Service engineĒ. We brought it to the dealership a few times to scan for a code and they couldnít come up with anything. So now we had to wait until it was actually happening and rush it over to the dealership so they can scan for the code while it was happening. Finally it was happening enough that we were able to get it to the dealer for the scan. The scan revealed that spark plug #1 was fouled and would cause a chain reaction on all the computers to go haywire. So they did a little research and they found a GM TSB (technical service bulletin) that said replace the valve cover gasket, replace all the plugs and wires. Keep in mind these are 100K mile platinum plugs/wires and we currently have around 79000 miles on the vehicle (GM recommends replacing these items at 100K miles). So we did what we were told and $700 later we were on our merry way.
Jump forward to January 2013. Now we start hearing a clunking sound on acceleration. We bring it back to the dealer and they canít seem to find anything (of course not????). Now February the sound is more apparent and all the warning lights have come back. I decided to take the car to a friend of mine who has a local shop and specializes in foreign autos. I knew he would take the time and do the research to finally tell us what the dealer couldnít. After having the car for a week the verdict was in. GM has this fuel management system introduced on this particular 5.3L motor in 2007. Itís supposed to be able to switch from 8 to 4 cylinders and back to help save on fuel (Active Fuel Management or AFM). To confirm the problem he would have to tear down the engine and check the intake valve on cylinder #1. This is when I said ďIím taking it back to the dealerĒ.
Now the dealership has the car and I didnít mention that I already had it looked at. I wanted to see if they would come up with the same diagnosis. Well after a week they did. I canít believe it since the initial $700 fix 3000 miles ago in November 2012 I now have to replace the engine, WTF! Needless to say I was not a happy camper. Now the car has been out of warranty for a little over a year (which has been pointed out to me over and over again) but thatís not the point. The point is we bought a brand new car so we wouldnít have any problems usually associated with used cars. A car that has less than 100K miles on it. A car that has been religiously serviced by our local Chevy Dealership. And now Iím being told I have to replace the motor!
The dealership called GM. GM was quick to say they would replace the motor and cover 50% of the costs? Well whoop de doo. Why were they so quick to offer that deal? Of course they are replacing it with a genuine GM remanufactured motor with a 3 year/ 50K warranty and thatís all they are willing to do. I donít expect the dealership to cover all the costs and it would be nice if I wasnít out of pocket any. Yes I know the car it out of warranty but I expect GM to back up their product. Did I mention I have purchased over $100K in new Chevy vehicles over the last several years.
So the car is no good to us. Canít drive it, sell it or trade it in. I basically have to take the deal. My estimated out of pocket will be $3K plus tax.
So I decided to call GM directly and talk to them in a kind Christian sort of way (as only I can do). I figured if they heard from the customer directly that they would be willing to at least come down a little. I know the car isnít under warranty. The results were not what I was looking for. After they gathered all the information from the dealership and me as well they will only cover 50% of the cost. I explained to them that Iíve been a loyal customer, this car had less than 100K miles on it, Iíve spent over $100K in Chevy cars over the last several years. Nope all they would do is 50%. I asked would they would at least reimburse me for the $700 that I already spent that was totally unnecessary? Nope only 50%. Well letís just say things went pretty much south from there.
So here is where we stand. The dealership is putting in the new motor. They are working with me to get the price down under $3K. I donít begrudge the dealership I think they did what they could do (as personally later found out with GM). I donít begrudge the lady at GM Iím sure she has set parameters she has to follow and sheís just a drone in the corporation. However I do begrudge GM for not standing by their product. Do the research itís all over the internet. GM has a problem with this motor and itís ďActive Fuel ManagementĒ they know it and they will continue to have problems. Unfortunately if you do have this particular motor thereís no way to check if you will have this problem or not. I will never buy a GM product again. They have lost a loyal customer over $700.
#345 of 415 Re: More GM AFM Pain! [msw007]
Mar 12, 2013 (8:30 pm)
How long do you think GM should be responsible for your car? 3000 dollars is a deal for a GM backed motor-take it!
#346 of 415 Re: More GM AFM Pain! [chuck1919]
Mar 13, 2013 (5:50 am)
Dumb question. Of course it's a good price....a good price on a new motor that should not have to be purchased for a vehicle with 80k miles. When the vehicle goes out of warranty u understand that maybe u will need to repair an alternator, battery, fuel filter, fuel pump, oil pump, etc. u don't expect to replace a damn motor. AND if u r the only person with this problem, it would make it easier to swallow having to pay for such a repair. But when u see this problem is rampant and GM is hiding from it even though they know the AFM has a serious design flaw, it really pisses people off. They lost my future business for ever with almost the exact same story as above. I've bought a new chevrolet truck every 4-5 years since 94. No more. EVER! And I tell everyone about this design flaw and what GM actually does about it. My sister actually bought a Ford Edge instead of a Chevy Traverse simply because of my experience. It's a shame. It's not the same Chevrolet that my dad was a fan of.
#347 of 415 Re: More GM AFM Pain! [chuck1919]
Mar 13, 2013 (8:58 am)
I agree with churchy25. I could see replacing some minor things under 83000 miles but to replace an entire motor??
This is a GM design flaw and they are hiding behind the warranty issue. I have never argued the fact that $3000 for the motor was not a good deal. I just want GM to admit they have a bad design flaw and they have to take care of it. I'm sure GM is betting on the come that these motors will start failing after 100K miles and then they can say too bad so sad to the consumer.
The problem is these motors are failing at an alarming rate at 50K miles with 75K-85K being the sweet spot for failure. So cars my age are starting to get to that mileage and pretty soon there are going to be a whole lot of pissed off consumers out there.
If you have your heart set on a GM vehicle (2007 and newer) with this motor then I strongly urge you to purchase the extended warranty.
#348 of 415 2011 sierra with afm/mileage issues
Mar 13, 2013 (10:20 am)
My2011 sierra 5.3 afm gets 16-17mpg around town or highway.it has a hard time staying in 4cly mode even at 45mph.several times its run 55+mph and had no problem staying in 4cyl mode also showed very good mpg on instant readout.sometimes aroundtown it will do same, but get it in v8mode it will not return to state of operation as before.been to dealer and had it checked out-everything ok.ive heard rumors of these trucks running 6o+mph on 4cyls and 20+mpg also heard about a lot like mine.im starting to think some of these have an inherent problem, with software or whatever. Id like to hear from others about performance/fixes etc.
#349 of 415 Follow up on Chevy 5.3L w/AFM
Mar 26, 2013 (4:13 pm)
Well we have the new remanufactured motor installed.
I spoke with the mechanic at the dealership and asked what exactly happened and if this was normal?
He told me the rings on the piston were worn and caused the leak by which fouled the plug. The cylinder wall were scarred and the other cylinders were starting to look worn.
He just shrugged his shoulders when I asked him if this was normal (that kind of says it all right there).
I know Black Bear Performance offers a tune solution to turn the AFM off. I guess they started to offer this due to the rash of complaints and problems that have been associated with this.
I have sent letters off to GM's upper management pleading my case. I'm not expecting much but it doesn't hurt to try.
#350 of 415 V8-V4 Fixes
Mar 26, 2013 (5:04 pm)
There is a company called Range Technology that sells "black boxes". They sell one that will either keep you in 4 cylinder mode longer or one that keeps it in V8 mode only. They plug in to your diagnostic port AND LEAVES NO TRACE ON THE ECM.
#351 of 415 Re: Follow up on Chevy 5.3L w/AFM [msw007]
Apr 02, 2013 (3:22 pm)
So I received a phone call from GM Corporate (my letters got through). I have spoke with him several times and as of now GM is holding firm on the 50/50. They say because I accepted the deal there's nothing else they can do? I reminded him I accepted the deal because I had a useless car and it had to be fixed (holding a gun to my head).
I told him right up front I'm not looking to get off without paying anything. I understand the car was out of warranty but the fact of the matter is the engine failed under 100K miles.
He said there were a few more upper management people he could plead my case to. So I don't know if he's blowing smoke up my a** or he's being truthful. We'll see.