Upon driving the engine began making extreme noise and major loss of power. Multiple engine lights came on and backfire through exhaust. Contacted Chevy dealer and dropped off for diagnosis. Problem was active fuel management lifter failure. (please take note that this issue is all over the internet and social media) this problem is happening to a high volume of Silverado truck manufactured after 2007 with afm. Chevrolet has bulletins on the issue but will not recall to replace all afm lifters. They only replace the lifters that fail. This causes issues later when additional lifters fail. If all aafm lifters (8) would be replaced at the same time consumers wouldn't be complaining via social media and internet. Chevrolet acknowledges the problem but refuses to recall. Reason for refusal is it seems to happen around 50,000 miles and above and after the repair they hope that the issue happens after the 100,000 mile warranty when repairs are paid for by consumers costing thousands of dollars. I personally have read of this happening and had it happen just recently. GM refuses to back their product although they recognize the problem. Bulletins have been issued but I was told that the NHTSA makes the call after enough complaints are filed by consumers. People just don't know this and I am requesting you urgently look into this issue. Catastrophic engine failure can result costing consumers a lot of money. We are just the little guy up against a large automobile manufacturer. We need your assistance in forcing GM to issue a recall on these vehicles with the active fuel management. Our hands are tied because of this. We request that if there is a afm lifter failure that all lifters be replaced instead of the ones that failed. This is only logical especially when GM knows there is a problem. Please help us the consumer.

- Sarver, PA, USA

Excessive oil consumption - truck runs out of oil every 2500 miles. Change it regularly. No leaks or blue smoke.

- San Antonio, TX, USA

Our 2007 Chevrolet 3500 4 X 4 with a 6.0 gas engine has failure in the exhaust manifold bolts and is causing noise and emission issues in and outside the cabin and is affecting horse power. Our truck has now 13,000 miles on it! thirteen thousand. It is well cared for and little used, there is no excuse that we face a thousand dollar or more bill to repair a unit that is a long way from being a used unit. We know of many now, that have this issue, our friend said he would not pay the dealer to do it for his truck, there is no service bulletin and no recall, but it was affecting everything, and you could not gain access to the broken bolts unless you tore out the top end of the motor, so he removed the motor and rebuilt these parts himself, it cost him he said $700 to do it himself. He is still mad about it. We are writing you in hopes that you may investigate and help, there are emission violations in many states due to this, and there can be a fire, it can affect the sensors and will trigger codes causing engine light to remain on. This problem affects nearly 7 or 8 years of GM trucks, 4.8, 5.7 and the 6.0 size engines. At first it was not too bad, but it has gotten worse in the past few thousand miles. The mileage of seven thousand is my approximation of when I first heard it, I thought it was exhaust, but I thought a protective plate over the muffler or something, no way did I think the bolts of the manifold were breaking. Please help us out on this.

- Minneapolis, MN, USA

Exhaust manifold bolts on the 6.0L break off at the head causing exhaust gas to leak into passenger compartment and potential for a fire. We have 10 trucks around this year and most or all have had all exhaust studs replaced. My local dealer is aware of this the service manager told me it happens to all 6.0L engines.

- Cresaptown, MD, USA

The contact owns a 2007 Chevrolet Silverado 3500. The contact stated while driving 70 mph the vehicle stalled. The contact stated the failure occurred at least four times since he owned it and feared the vehicle could stall while towing and cause a crash. The contact took the vehicle to the dealer and they reprogrammed the computer. The contact stated the repair only remedies the issue temporarily. The contact was concerned since the vehicle was unsafe to drive. The failure mileage was 70,000.

- Oregon City, OR, USA

I took my new Chevy truck into the dealer for some new factory equipment (bug deflector and bed liner) to be installed by them. While the dealer had my 2007 Chevy truck they loaded 2008 power train software into it's computer without my permission. The 2008 software changed the way my truck runs. The power train now has a speed limiter on it and the stability control was changed. It will not go as fast it as use to go before the change. I was told by the dealer and GM they would not put my truck back the way it was as when I bought it. They told me that the reason was the Goodyear tires and the truck design were unsafe without the 2008 software installed and would not change my truck back to the 2007 configration. I have not gotten any recall or safety notices about this issue. I think GM and the dealer made a mistake and do not want to correct it. If there is a problem with the tires (Goodyear Wrangler tires) and the 2007 truck design (GM Silverado 1500 lts crew cab) GM is trying to cover it up. There are hundreds of thousands of 2007 GM trucks, cars, SUV's even Cadillac's that have the same power train in them that my truck has and they are not changing the computer programs in all those vehicles. I was told they would be changed only if the trucks, SUV's and cars were brought in for any kind of service work, but would not be changed if not serviced by GM. Sense there have been no recall notices about these issues I think GM is trying to cover something up. The very least trying to cover up their dealers and there mistake by altering my truck without my permission or they do have a serious problem that the public should be aware of. Please look into this. The same tires are on Ford and Dodge and they don't software limit there performance. I paid top dollar for GM's best truck with the biggest engine made for it, I could have saved a lot of money by buying a six cylinder engine instead of the big V-8. if I knew GM was going to de-rate mine.

- Tucson, AZ, USA

The contact owns a 2007 Chevrolet Silverado 3500 duramax diesel truck. While driving 65 mph, the vehicle lost power and would not accelerate above first gear. The failure occurred on two separate occasions. The computer has been reset a total of three times. Recall number 08142 (engine control module) was referenced. The contact is preparing to take another trip and is concerned that the engine will lose power again. The failure mileage was 500.

- Mentor, OH, USA