2004 Gmc Sierra 2500 Hd Slt Extended Cab Pickup 4-door 8.1l on 2040-cars

Auto blog

GM recalling 686k Lambda-platform models for hatch repair

General Motors is recalling 686,287 units of its Lambda platform crossovers. On models equipped with a power rear hatch the system can potentially fail. This campaign includes the 2008-2012 Buick Enclave, 2009-2012 Chevrolet Traverse, 2007-2012 GMC Acadia, and 2007-2010 Saturn Outlook. According to GM's documents to the National Highway Traffic Safety Administration (as a PDF), dirt can get into a portion of the strut that holds up the hatch and cause the part to prematurely fail. There's a redundancy in place called the Prop Rod Recovery system that's designed to shut the liftgate if there's a malfunction. However, if the breakdown happens too quickly after the hatch is opened the prop rod might not work the way it's supposed to. If someone were in the way of the falling liftgate, they could be hurt. For the repair, dealers will update the software for the power liftgate actuator motor control unit to prevent the hatch from closing so quickly. They'll also check the operation of the system afterward. Related Video: RECALL Subject : Liftgate Struts may Fail and Liftgate may Fall Report Receipt Date: JUN 30, 2015 NHTSA Campaign Number: 15V415000 Component(s): STRUCTURE Potential Number of Units Affected: 686,287 All Products Associated with this Recall Vehicle Make Model Model Year(s) BUICK ENCLAVE 2008-2012 CHEVROLET TRAVERSE 2009-2012 GMC ACADIA 2007-2012 SATURN OUTLOOK 2007-2010 Details Manufacturer: General Motors LLC SUMMARY: General Motors LLC (GM) is recalling certain model year 2008-2012 Buick Enclave vehicles manufactured January 3, 2007, to February 29, 2012, 2009-2012 Chevrolet Traverse vehicles manufactured July 6, 2008, to February 29, 2012, 2007-2012 GMC Acadia vehicles manufactured September 15, 2006, to February 29, 2012, and 2007-2010 Saturn Outlook vehicles manufactured August 17, 2006, to March 18, 2010. The affected vehicles, equipped with the power liftgate option, have gas struts that hold the power liftgate up when open. These struts may prematurely wear and the open liftgate may suddenly fall. CONSEQUENCE: If the open liftgate unexpectedly falls, it may strike a person, increasing their risk of injury. REMEDY: GM will notify owners, and dealers will update the software for the power liftgate actuator motor control unit so that the motor will prevent the rapid closing of the lift gate, free of charge. The manufacturer has not yet provided a notification schedule.

Chevy's 6.6-liter Duramax is pretty much all new

To say there's a heated battle in heavy-duty pickups is an understatement, with Chevrolet, Ford, and Ram constantly trading blows of increased torque, horsepower, and towing capacity. The latest salvo is the revised, more powerful turbo diesel 6.6-liter Duramax V8 in the 2017 Chevy Silverado. It has 910 pound-feet of torque, an increase of 145, putting it nearly level with the Ford Super Duty. Here's a closer look at where those gains come from. How exactly did Chevrolet add all that torque plus 48 horsepower? The automaker essentially took a fine-tooth comb to the entire engine. Chevy says it changed 90 percent of the V8, and the cumulative effect of those small changes adds up to big increases. As you might guess, the turbocharger is updated. The larger unit features electric actuation of the variable nozzle turbine (VNT), and what Chevy calls a double axle cartridge mechanism that separates the VNT moving parts from the housing. That helps with heat performance as well, with a claim that the exhaust side of the turbo can run continuously up to 1,436 degrees Fahrenheit. Helping that cause are six exhaust gaskets made of Inconel - an nickel alloy that contains chromium and iron – and upgraded stainless steel for the exhaust manifold. Despite having the same cast iron cylinder block, albeit with some minor enhancements, the engine has new cylinder heads, pistons, piston pins, connecting rods, and crankshaft, which have all been upgraded to handle 20 percent higher cylinder pressures. Alongside the increase in pressure, Chevrolet also increased the cylinder head's structure with a honeycomb design. The pattern features high-strength aluminum with dual layer water jackets that not only improve strength, but also optimize water flow for better cooling. For 2017, the cylinder head also benefits from integrated plenum that aids the engine in getting more air under heavy loads. The cylinder head isn't the only component to get a minor update, as the pistons have a larger diameter pin for improved oil flow. The same detailed improvements has been bestowed to the humble connecting rods (second in our hearts only to the inanimate carbon rod). The new design has the bolts oriented roughly 45-degrees to the rod instead of parallel. The angle split design, as it's called allows for easier passage through the cylinder.

GM exploring ways to raise half-ton Duramax diesel tow rating

Lots of truck owners cheered when GM announced fuel economy numbers for the 2020 Chevrolet Silverado with the 3.0-liter Duramax diesel inline-six. Even after Ram let loose its EPA mileage ratings for the 2020 Ram 1500 EcoDiesel, the Chevy oil-burner still took the trophy. The victory was years in the making, GM engineers spending an entire four-year development cycle refining the LM2 Duramax to increase mileage. The tradeoff, as well all know by now, is towing; the Duramax in half-ton duty pulls a maximum 9,300 pounds in the Silverado. Rivals across town can do more, the Ford F-150 PowerStroke rated at 11,500, the Ram 1500 EcoDiesel game to pull 12,560. GM engineer John Barta told Muscle Cars & Trucks that more hauling chops could be on the way, explaining, "We’re actually looking at upgrading some of the materials around (the engine bay) to see if we can maybe raise our tow rating." Engine bay materials are at issue due to thermal complexities underhood. John Barta, GM's assistant chief engineer of diesel engine controls, said the Duramax's inline-six configuration allowed engineers to get emissions hardware like the combined selective catalytic reduction, diesel oxidation catalysts, and diesel particulate filter unit closer to the engine, where it heats up quicker, getting emissions down quicker. But that filter puts another heat source in those confines, enforcing a cap on the tow rating to keep the engine and other systems from overheating. "If you look under the hood," he said, "youÂ’ll see a significant amount of silver ‘moon tapeÂ’ around to make sure things arenÂ’t getting overheatedÂ… if we were to go up in higher towing, which we can, we start impacting the possibility of deteriorating some of the components.” There isn't much space for more grille, so swapping for a better grade of "moon tape" or a different kind of material could reduce engine bay heat, extracting a higher tow rating in the process.  It's important to note a point Barta's been making for months about the Duramax figures, though. "Even though itÂ’s nice to brag about big numbers, in reality, light duty customers are not towing that large with their trucks," and, "We do know that (95 percent) of our light duty customers donÂ’t tow over 9,000 pounds." On our First Drive of the 2020 Silverado diesel we called out the tow rating, but emphasized that the Chevy and GMC have more important challenges to overcome.