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2007/2008 Silverado and Sierra Active Fuel Management Problems

106 messages, Last post on Sep 01, 2009 at 9:04 PM
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Replying to: natesms (Feb 04, 2008 8:46 am) I do notice that if I drive regularly above 70, the AFM does not kick in as much, and it seems to stay off if I am pushing 80...which is normally too fast for me. So far my truck has proven to be world-class in every way. If I could have waited another 9 months I would have ordered with the soon to be released 6 speed transmission.
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Replying to: fhaines (Feb 10, 2008 6:47 am)
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Replying to: fueledup (Feb 10, 2008 12:28 pm) "Current predictions have EPA estimates hovering around 16 mpg in the city/21 mpg on the highway with the 5.3-liter V-8. Expect that number to improve when the six-speed transmission replaces the four-speed (both column shifters with an improved hand-contoured grip) in the SUVs and pickups in the next model year." I have not see much supporting documentation since. I am attaching the link from which this was quoted, the link is: http://www.motortrend.com/features/112_0609_2007_chevrolet_silverado/options.htm- l I think GM has always intended to use the 6 speed when it becomes available, but the total volume of vehicles (GM builds) that can accommodate the 6 speed is greater than available units, hence the phase in. I doubt you could bank on a firm date for the 6-speed phase in. My truck with the 4-speed has plenty of power and holds its shift points well, even when I am towing. I was very skeptical about buying the truck with the 4-speed, however, this particular unit is one of GM's more robust units. I looked at the Tundra because it had a 6-speed transmission, but felt it was not as good a value, and the fit and finish was better on the Chevy. You will not be disappointed with your LTZ selection as configured, I remain completely impressed with mine at now 15K and counting. I just finished a road trip today, in 4 Auto, in snow, ice and rain, and got 18.2 MPG.
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Replying to: fhaines (Feb 13, 2008 9:13 pm) |
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Well, I have the 5.3 on my "new" chevy 1500 2wd extended cab that is supposed to have the AFM. Ive put 22,000 miles on it since memorial day and have yet to achieve anything better than 18-19 (19 on a good day) MPG. BTW, the sticker said 22 hiway. My question for those who know, is if you have the truck without the DIC buttons, how would you know if AFM is active or not? The book says there is a display regardless of whether you have the DIC buttons or not, but fails to mention how one would know. I drive many days from gas station to gas station only touching the brake pedal and ignition when I leave the first station, stopping at the next one. 60-65 mph, cruise on, all highway. I drove 948 miles this week and might have achieved 18 mpg if I rounded it up. I generally get about 400 - 420 miles per tank and my fill ups are between 22.5 - 24.5 gallons. My simple math tells me that if I were to get even 20mpg, I should go 440 miles on 22 gallons of gas. No, I dont see any indication that AFM even exists. The serial number says it has it, the sticker says it has it, but other than that, there is no indication that it exsists or if it does, that it functions. Ive even driven 2 tank fulls with the trailer button depressed only to find the same exact milage. I love the truck, dont get me wrong. It's not the most comfortable for 6 or 8 straight hours, but it's a truck. My question remains. How would one know when the engine goes to 4 cyl. My next question (assuming there is no way for joe truck owner to know) is how would the dealership test it? Can they hook a computer up to it and see it function, can they engage the EFI manually or however AFM works? How can they show me that it is doing what it says it is or for that matter, even show me that it's installed? 18 is ok? Thats 20% off the sticker. What if your wife was in the grocery store, bought $100 worth of groceries, and the store constantly failed to load more than 80% of those groceries in her trunk? What if you bought an air conditioner rated at 16 SEER only to find out it was a 13 SEER? What if the fuel stations only delivered 80% of the fuel the pump said it did? All I want to know is... Is it there, and if so, does it work (show me). It's a shame a coworker who has the same truck except his is 4wd and he gets over 20 per gallon with the same monthly miles and same type of driving. |
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is there a fuel pump in the single gas tank for a silverado 3500 duramax 6.6 ? also any suggested ideas on what to do when the truck doesnt start when it's cold or hot, mostly cold ? |
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This is my 5th truck which I ordered from the dealer in Maryland and picked up in January 08. After driving it about 200 miles I proceeded to drive to Ft Pierce, FL non stop. Generally speaking, I drove 5 to 7mph over the posted limit e.g. in a 55 zone I drove up to 62, in a 70 zone I drove up to 77.....almost always on 'cruse control'.......my average for the trip was 18.4 mpg and the truck performed flawlessly. I now have 6000+ miles on the truck and it consistently 'averages' in the 16-17 area (mostly short 'around-town' runs). I find that the AFM is NOT noticeable by passengers but IS noticeable by me....though now I find I'v become oblivious to it!! This truck is a 5.3L, 4X4, LTZ with Stabilitrak. My last two trucks were a Dodge 2500 Diesel and a Chevrolet 2500HD Diesel respectively.......this '08 truck is far more economical than the Dodge and equal to the Duramax, though, I'm sure, it won't tow as much....its all a balancing act....the diesels are a $10K additive cost and the diesel fuel is 12 to 15% more expensive than regular......bottom line is that if you are not towing high weight trailers frequently it is far better to go with the gas truck! Prior to the Diesels I owned a Nissan and a Toyota.......wasn't happy with either of them!! |
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I have a 2008 chevy silverado with a 5.3 and active fuel management. I am wondering if there is a way to tell when the truck is running on 4 or 8 cylinders. Can you hook up a test light or something to that effect,
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| I have heard that there is an issue with the Fuel management system when you put on a duel catbak exhaust. When it shifts to 4 cyl it makes a roaring sound? is this true and if so what luck has anyone had with finding one to put on an 08 silverado 1500? | |
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